Bluetooth: iso: Fix circular lock in iso_listen_bis

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: iso: Fix circular lock in iso_listen_bis

This fixes the circular locking dependency warning below, by

releasing the socket lock before enterning iso_listen_bis, to

avoid any potential deadlock with hdev lock.

[ 75.307983] ======================================================

[ 75.307984] WARNING: possible circular locking dependency detected

[ 75.307985] 6.12.0-rc6+ #22 Not tainted

[ 75.307987] ------------------------------------------------------

[ 75.307987] kworker/u81:2/2623 is trying to acquire lock:

[ 75.307988] ffff8fde1769da58 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO)

at: iso_connect_cfm+0x253/0x840 [bluetooth]

[ 75.308021]

but task is already holding lock:

[ 75.308022] ffff8fdd61a10078 (&hdev->lock)

at: hci_le_per_adv_report_evt+0x47/0x2f0 [bluetooth]

[ 75.308053]

which lock already depends on the new lock.

[ 75.308054]

the existing dependency chain (in reverse order) is:

[ 75.308055]

-> #1 (&hdev->lock){+.+.}-{3:3}:

[ 75.308057] __mutex_lock+0xad/0xc50

[ 75.308061] mutex_lock_nested+0x1b/0x30

[ 75.308063] iso_sock_listen+0x143/0x5c0 [bluetooth]

[ 75.308085] __sys_listen_socket+0x49/0x60

[ 75.308088] __x64_sys_listen+0x4c/0x90

[ 75.308090] x64_sys_call+0x2517/0x25f0

[ 75.308092] do_syscall_64+0x87/0x150

[ 75.308095] entry_SYSCALL_64_after_hwframe+0x76/0x7e

[ 75.308098]

-> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:

[ 75.308100] __lock_acquire+0x155e/0x25f0

[ 75.308103] lock_acquire+0xc9/0x300

[ 75.308105] lock_sock_nested+0x32/0x90

[ 75.308107] iso_connect_cfm+0x253/0x840 [bluetooth]

[ 75.308128] hci_connect_cfm+0x6c/0x190 [bluetooth]

[ 75.308155] hci_le_per_adv_report_evt+0x27b/0x2f0 [bluetooth]

[ 75.308180] hci_le_meta_evt+0xe7/0x200 [bluetooth]

[ 75.308206] hci_event_packet+0x21f/0x5c0 [bluetooth]

[ 75.308230] hci_rx_work+0x3ae/0xb10 [bluetooth]

[ 75.308254] process_one_work+0x212/0x740

[ 75.308256] worker_thread+0x1bd/0x3a0

[ 75.308258] kthread+0xe4/0x120

[ 75.308259] ret_from_fork+0x44/0x70

[ 75.308261] ret_from_fork_asm+0x1a/0x30

[ 75.308263]

other info that might help us debug this:

[ 75.308264] Possible unsafe locking scenario:

[ 75.308264] CPU0 CPU1

[ 75.308265] ---- ----

[ 75.308265] lock(&hdev->lock);

[ 75.308267] lock(sk_lock-

AF_BLUETOOTH-BTPROTO_ISO);

[ 75.308268] lock(&hdev->lock);

[ 75.308269] lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);

[ 75.308270]

*** DEADLOCK ***

[ 75.308271] 4 locks held by kworker/u81:2/2623:

[ 75.308272] #0: ffff8fdd66e52148 ((wq_completion)hci0#2){+.+.}-{0:0},

at: process_one_work+0x443/0x740

[ 75.308276] #1: ffffafb488b7fe48 ((work_completion)(&hdev->rx_work)),

at: process_one_work+0x1ce/0x740

[ 75.308280] #2: ffff8fdd61a10078 (&hdev->lock){+.+.}-{3:3}

at: hci_le_per_adv_report_evt+0x47/0x2f0 [bluetooth]

[ 75.308304] #3: ffffffffb6ba4900 (rcu_read_lock){....}-{1:2},

at: hci_connect_cfm+0x29/0x190 [bluetooth]