linux-stable/net/bluetooth/hci_sysfs.c
Wei Yongjun 75d9b8559a Bluetooth: Fix memory leak of hci device
Fault injection test reported memory leak of hci device as follows:

unreferenced object 0xffff88800b858000 (size 8192):
  comm "kworker/0:2", pid 167, jiffies 4294955747 (age 557.148s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 ad 4e ad de  .............N..
  backtrace:
    [<0000000070eb1059>] kmem_cache_alloc_trace mm/slub.c:3208
    [<00000000015eb521>] hci_alloc_dev_priv include/linux/slab.h:591
    [<00000000dcfc1e21>] bpa10x_probe include/net/bluetooth/hci_core.h:1240
    [<000000005d3028c7>] usb_probe_interface drivers/usb/core/driver.c:397
    [<00000000cbac9243>] really_probe drivers/base/dd.c:517
    [<0000000024cab3f0>] __driver_probe_device drivers/base/dd.c:751
    [<00000000202135cb>] driver_probe_device drivers/base/dd.c:782
    [<000000000761f2bc>] __device_attach_driver drivers/base/dd.c:899
    [<00000000f7d63134>] bus_for_each_drv drivers/base/bus.c:427
    [<00000000c9551f0b>] __device_attach drivers/base/dd.c:971
    [<000000007f79bd16>] bus_probe_device drivers/base/bus.c:487
    [<000000007bb8b95a>] device_add drivers/base/core.c:3364
    [<000000009564d9ea>] usb_set_configuration drivers/usb/core/message.c:2171
    [<00000000e4657087>] usb_generic_driver_probe drivers/usb/core/generic.c:239
    [<0000000071ede518>] usb_probe_device drivers/usb/core/driver.c:294
    [<00000000cbac9243>] really_probe drivers/base/dd.c:517

hci_alloc_dev() do not init the device's flag. And hci_free_dev()
using put_device() to free the memory allocated for this device,
but it calls just put_device(dev) only in case of HCI_UNREGISTER
flag is set, So any error handing before hci_register_dev() success
will cause memory leak.

To avoid this behaviour we can using kfree() to release dev before
hci_register_dev() success.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2021-10-13 14:31:50 +02:00

120 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);
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);
}