Bluetooth: hci_sock: fix slab oob read in create_monitor_event

When accessing hdev->name, the actual string length should prevail

Reported-by: syzbot+c90849c50ed209d77689@syzkaller.appspotmail.com
Fixes: dcda1657 ("Bluetooth: hci_core: Fix build warnings")
Signed-off-by: Edward AD <twuufnxlz@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

net/bluetooth/hci_sock.c

@@ -488,7 +488,7 @@ static struct sk_buff *create_monitor_event(struct hci_dev *hdev, int event)
 		ni->type = hdev->dev_type;
 		ni->bus = hdev->bus;
 		bacpy(&ni->bdaddr, &hdev->bdaddr);
-		memcpy(ni->name, hdev->name, 8);
+		memcpy(ni->name, hdev->name, strlen(hdev->name));
 
 		opcode = cpu_to_le16(HCI_MON_NEW_INDEX);
 		break;