[PATCH 2/3] Bluetooth: Call iso_exit() on module unload

From: Aaron Thompson
Date: Thu Oct 03 2024 - 20:31:44 EST


From: Aaron Thompson <dev@xxxxxxxxxx>

If iso_init() has been called, iso_exit() must be called on module
unload. Without that, the struct proto that iso_init() registered with
proto_register() becomes invalid, which could cause unpredictable
problems later. In my case, with CONFIG_LIST_HARDENED and
CONFIG_BUG_ON_DATA_CORRUPTION enabled, loading the module again usually
triggers this BUG():

list_add corruption. next->prev should be prev (ffffffffb5355fd0),
but was 0000000000000068. (next=ffffffffc0a010d0).
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:29!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 1 PID: 4159 Comm: modprobe Not tainted 6.10.11-4+bt2-ao-desktop #1
RIP: 0010:__list_add_valid_or_report+0x61/0xa0
...
__list_add_valid_or_report+0x61/0xa0
proto_register+0x299/0x320
hci_sock_init+0x16/0xc0 [bluetooth]
bt_init+0x68/0xd0 [bluetooth]
__pfx_bt_init+0x10/0x10 [bluetooth]
do_one_initcall+0x80/0x2f0
do_init_module+0x8b/0x230
__do_sys_init_module+0x15f/0x190
do_syscall_64+0x68/0x110
...

Cc: stable@xxxxxxxxxxxxxxx
Fixes: ccf74f2390d6 ("Bluetooth: Add BTPROTO_ISO socket type")
Signed-off-by: Aaron Thompson <dev@xxxxxxxxxx>
---
net/bluetooth/mgmt.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index e4f564d6f6fb..78a164fab3e1 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -10487,6 +10487,7 @@ int mgmt_init(void)

void mgmt_exit(void)
{
+ iso_exit();
hci_mgmt_chan_unregister(&chan);
}

--
2.39.5