linux/net/bluetooth/hci_sysfs.c
Luiz Augusto von Dentz 448a496f76 Bluetooth: hci_sysfs: Fix attempting to call device_add multiple times
device_add shall not be called multiple times as stated in its
documentation:

 'Do not call this routine or device_register() more than once for
 any device structure'

Syzkaller reports a bug as follows [1]:
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:33!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
[...]
Call Trace:
 <TASK>
 __list_add include/linux/list.h:69 [inline]
 list_add_tail include/linux/list.h:102 [inline]
 kobj_kset_join lib/kobject.c:164 [inline]
 kobject_add_internal+0x18f/0x8f0 lib/kobject.c:214
 kobject_add_varg lib/kobject.c:358 [inline]
 kobject_add+0x150/0x1c0 lib/kobject.c:410
 device_add+0x368/0x1e90 drivers/base/core.c:3452
 hci_conn_add_sysfs+0x9b/0x1b0 net/bluetooth/hci_sysfs.c:53
 hci_le_cis_estabilished_evt+0x57c/0xae0 net/bluetooth/hci_event.c:6799
 hci_le_meta_evt+0x2b8/0x510 net/bluetooth/hci_event.c:7110
 hci_event_func net/bluetooth/hci_event.c:7440 [inline]
 hci_event_packet+0x63d/0xfd0 net/bluetooth/hci_event.c:7495
 hci_rx_work+0xae7/0x1230 net/bluetooth/hci_core.c:4007
 process_one_work+0x991/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e4/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Link: https://syzkaller.appspot.com/bug?id=da3246e2d33afdb92d66bc166a0934c5b146404a
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Tested-by: Hawkins Jiawei <yin31149@gmail.com>
2022-09-21 15:00:54 -07:00

124 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Bluetooth HCI driver model support. */
#include <linux/module.h>
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
static struct class *bt_class;
static void bt_link_release(struct device *dev)
{
struct hci_conn *conn = to_hci_conn(dev);
kfree(conn);
}
static const struct device_type bt_link = {
.name = "link",
.release = bt_link_release,
};
/*
* The rfcomm tty device will possibly retain even when conn
* is down, and sysfs doesn't support move zombie device,
* so we should move the device before conn device is destroyed.
*/
static int __match_tty(struct device *dev, void *data)
{
return !strncmp(dev_name(dev), "rfcomm", 6);
}
void hci_conn_init_sysfs(struct hci_conn *conn)
{
struct hci_dev *hdev = conn->hdev;
BT_DBG("conn %p", conn);
conn->dev.type = &bt_link;
conn->dev.class = bt_class;
conn->dev.parent = &hdev->dev;
device_initialize(&conn->dev);
}
void hci_conn_add_sysfs(struct hci_conn *conn)
{
struct hci_dev *hdev = conn->hdev;
BT_DBG("conn %p", conn);
if (device_is_registered(&conn->dev))
return;
dev_set_name(&conn->dev, "%s:%d", hdev->name, conn->handle);
if (device_add(&conn->dev) < 0) {
bt_dev_err(hdev, "failed to register connection device");
return;
}
hci_dev_hold(hdev);
}
void hci_conn_del_sysfs(struct hci_conn *conn)
{
struct hci_dev *hdev = conn->hdev;
if (!device_is_registered(&conn->dev))
return;
while (1) {
struct device *dev;
dev = device_find_child(&conn->dev, NULL, __match_tty);
if (!dev)
break;
device_move(dev, NULL, DPM_ORDER_DEV_LAST);
put_device(dev);
}
device_del(&conn->dev);
hci_dev_put(hdev);
}
static void bt_host_release(struct device *dev)
{
struct hci_dev *hdev = to_hci_dev(dev);
if (hci_dev_test_flag(hdev, HCI_UNREGISTER))
hci_release_dev(hdev);
else
kfree(hdev);
module_put(THIS_MODULE);
}
static const struct device_type bt_host = {
.name = "host",
.release = bt_host_release,
};
void hci_init_sysfs(struct hci_dev *hdev)
{
struct device *dev = &hdev->dev;
dev->type = &bt_host;
dev->class = bt_class;
__module_get(THIS_MODULE);
device_initialize(dev);
}
int __init bt_sysfs_init(void)
{
bt_class = class_create(THIS_MODULE, "bluetooth");
return PTR_ERR_OR_ZERO(bt_class);
}
void bt_sysfs_cleanup(void)
{
class_destroy(bt_class);
}