[v7] Bluetooth: Fix possible race with userspace of sysfs isoc_alt

Commit Message

Hsin-chen Chuang Feb. 19, 2025, 2:02 p.m. UTC

From: Hsin-chen Chuang <[e-mail]>

Expose the isoc_alt attr with device group to avoid the racing.

Now we create a dev node for btusb. The isoc_alt attr belongs to it and
it also becomes the parent device of hci dev.

Fixes: b16b327edb4d ("Bluetooth: btusb: add sysfs attribute to control USB alt setting")
Signed-off-by: Hsin-chen Chuang <[e-mail]>
---

Changes in v7:
- Use container_of() rather than dev_set_drvdata() + dev_get_drvdata()

Changes in v6:
- Fix EXPORT_SYMBOL -> EXPORT_SYMBOL_GPL
- Use container_of() rather than dev_set_drvdata() + dev_get_drvdata()

Changes in v5:
- Merge the ABI doc into this patch
- Manage the driver data with device

Changes in v4:
- Create a dev node for btusb. It's now hci dev's parent and the
  isoc_alt now belongs to it.
- Since the changes is almost limitted in btusb, no need to add the
  callbacks in hdev anymore.

Changes in v3:
- Make the attribute exported only when the isoc_alt is available.
- In btusb_probe, determine data->isoc before calling hci_alloc_dev_priv
  (which calls hci_init_sysfs).
- Since hci_init_sysfs is called before btusb could modify the hdev,
  add new argument add_isoc_alt_attr for btusb to inform hci_init_sysfs.

Changes in v2:
- The patch has been removed from series

 .../ABI/stable/sysfs-class-bluetooth          |  13 ++
 drivers/bluetooth/btusb.c                     | 114 +++++++++++++-----
 include/net/bluetooth/hci_core.h              |   1 +
 net/bluetooth/hci_sysfs.c                     |   3 +-
 4 files changed, 103 insertions(+), 28 deletions(-)

Comments

Hsin-chen Chuang Feb. 21, 2025, 1:42 a.m. UTC | #1

On Wed, Feb 19, 2025 at 10:03 PM Hsin-chen Chuang <[e-mail]> wrote:
>
> From: Hsin-chen Chuang <[e-mail]>
>
> Expose the isoc_alt attr with device group to avoid the racing.
>
> Now we create a dev node for btusb. The isoc_alt attr belongs to it and
> it also becomes the parent device of hci dev.
>
> Fixes: b16b327edb4d ("Bluetooth: btusb: add sysfs attribute to control USB alt setting")
> Signed-off-by: Hsin-chen Chuang <[e-mail]>
> ---
>
> Changes in v7:
> - Use container_of() rather than dev_set_drvdata() + dev_get_drvdata()
>
> Changes in v6:
> - Fix EXPORT_SYMBOL -> EXPORT_SYMBOL_GPL
> - Use container_of() rather than dev_set_drvdata() + dev_get_drvdata()
>
> Changes in v5:
> - Merge the ABI doc into this patch
> - Manage the driver data with device
>
> Changes in v4:
> - Create a dev node for btusb. It's now hci dev's parent and the
>   isoc_alt now belongs to it.
> - Since the changes is almost limitted in btusb, no need to add the
>   callbacks in hdev anymore.
>
> Changes in v3:
> - Make the attribute exported only when the isoc_alt is available.
> - In btusb_probe, determine data->isoc before calling hci_alloc_dev_priv
>   (which calls hci_init_sysfs).
> - Since hci_init_sysfs is called before btusb could modify the hdev,
>   add new argument add_isoc_alt_attr for btusb to inform hci_init_sysfs.
>
> Changes in v2:
> - The patch has been removed from series
>
>  .../ABI/stable/sysfs-class-bluetooth          |  13 ++
>  drivers/bluetooth/btusb.c                     | 114 +++++++++++++-----
>  include/net/bluetooth/hci_core.h              |   1 +
>  net/bluetooth/hci_sysfs.c                     |   3 +-
>  4 files changed, 103 insertions(+), 28 deletions(-)
>
> diff --git a/Documentation/ABI/stable/sysfs-class-bluetooth b/Documentation/ABI/stable/sysfs-class-bluetooth
> index 36be02471174..c1024c7c4634 100644
> --- a/Documentation/ABI/stable/sysfs-class-bluetooth
> +++ b/Documentation/ABI/stable/sysfs-class-bluetooth
> @@ -7,3 +7,16 @@ Description:   This write-only attribute allows users to trigger the vendor reset
>                 The reset may or may not be done through the device transport
>                 (e.g., UART/USB), and can also be done through an out-of-band
>                 approach such as GPIO.
> +
> +What:          /sys/class/bluetooth/btusb<usb-intf>/isoc_alt
> +Date:          13-Feb-2025
> +KernelVersion: 6.13
> +Contact:       [e-mail]
> +Description:   This attribute allows users to configure the USB Alternate setting
> +               for the specific HCI device. Reading this attribute returns the
> +               current setting, and writing any supported numbers would change
> +               the setting. See the USB Alternate setting definition in Bluetooth
> +               core spec 5, vol 4, part B, table 2.1.
> +               If the HCI device is not yet init-ed, the write fails with -ENODEV.
> +               If the data is not a valid number, the write fails with -EINVAL.
> +               The other failures are vendor specific.
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index de3fa725d210..495f0ceba95d 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -920,6 +920,8 @@ struct btusb_data {
>         int oob_wake_irq;   /* irq for out-of-band wake-on-bt */
>
>         struct qca_dump_info qca_dump;
> +
> +       struct device dev;
>  };
>
>  static void btusb_reset(struct hci_dev *hdev)
> @@ -3682,7 +3684,7 @@ static ssize_t isoc_alt_show(struct device *dev,
>                              struct device_attribute *attr,
>                              char *buf)
>  {
> -       struct btusb_data *data = dev_get_drvdata(dev);
> +       struct btusb_data *data = container_of(dev, struct btusb_data, dev);
>
>         return sysfs_emit(buf, "%d\n", data->isoc_altsetting);
>  }
> @@ -3691,10 +3693,13 @@ static ssize_t isoc_alt_store(struct device *dev,
>                               struct device_attribute *attr,
>                               const char *buf, size_t count)
>  {
> -       struct btusb_data *data = dev_get_drvdata(dev);
> +       struct btusb_data *data = container_of(dev, struct btusb_data, dev);
>         int alt;
>         int ret;
>
> +       if (!data->hdev)
> +               return -ENODEV;
> +
>         if (kstrtoint(buf, 10, &alt))
>                 return -EINVAL;
>
> @@ -3704,6 +3709,36 @@ static ssize_t isoc_alt_store(struct device *dev,
>
>  static DEVICE_ATTR_RW(isoc_alt);
>
> +static struct attribute *btusb_sysfs_attrs[] = {
> +       NULL,
> +};
> +ATTRIBUTE_GROUPS(btusb_sysfs);
> +
> +static void btusb_sysfs_release(struct device *dev)
> +{
> +       struct btusb_data *data = container_of(dev, struct btusb_data, dev);
> +
> +       kfree(data);
> +}
> +
> +static const struct device_type btusb_sysfs = {
> +       .name    = "btusb",
> +       .release = btusb_sysfs_release,
> +       .groups  = btusb_sysfs_groups,
> +};
> +
> +static struct attribute *btusb_sysfs_isoc_alt_attrs[] = {
> +       &dev_attr_isoc_alt.attr,
> +       NULL,
> +};
> +ATTRIBUTE_GROUPS(btusb_sysfs_isoc_alt);
> +
> +static const struct device_type btusb_sysfs_isoc_alt = {
> +       .name    = "btusb",
> +       .release = btusb_sysfs_release,
> +       .groups  = btusb_sysfs_isoc_alt_groups,
> +};
> +
>  static int btusb_probe(struct usb_interface *intf,
>                        const struct usb_device_id *id)
>  {
> @@ -3745,7 +3780,7 @@ static int btusb_probe(struct usb_interface *intf,
>                         return -ENODEV;
>         }
>
> -       data = devm_kzalloc(&intf->dev, sizeof(*data), GFP_KERNEL);
> +       data = kzalloc(sizeof(*data), GFP_KERNEL);
>         if (!data)
>                 return -ENOMEM;
>
> @@ -3768,8 +3803,10 @@ static int btusb_probe(struct usb_interface *intf,
>                 }
>         }
>
> -       if (!data->intr_ep || !data->bulk_tx_ep || !data->bulk_rx_ep)
> -               return -ENODEV;
> +       if (!data->intr_ep || !data->bulk_tx_ep || !data->bulk_rx_ep) {
> +               err = -ENODEV;
> +               goto out_free_data;
> +       }
>
>         if (id->driver_info & BTUSB_AMP) {
>                 data->cmdreq_type = USB_TYPE_CLASS | 0x01;
> @@ -3823,16 +3860,46 @@ static int btusb_probe(struct usb_interface *intf,
>
>         data->recv_acl = hci_recv_frame;
>
> +       if (id->driver_info & BTUSB_AMP) {
> +               /* AMP controllers do not support SCO packets */
> +               data->isoc = NULL;
> +       } else {
> +               /* Interface orders are hardcoded in the specification */
> +               data->isoc = usb_ifnum_to_if(data->udev, ifnum_base + 1);
> +               data->isoc_ifnum = ifnum_base + 1;
> +       }
> +
> +       if (id->driver_info & BTUSB_BROKEN_ISOC)
> +               data->isoc = NULL;
> +
> +       /* Init a dev for btusb. The attr depends on the support of isoc. */
> +       if (data->isoc)
> +               data->dev.type = &btusb_sysfs_isoc_alt;
> +       else
> +               data->dev.type = &btusb_sysfs;
> +       data->dev.class = &bt_class;
> +       data->dev.parent = &intf->dev;
> +
> +       err = dev_set_name(&data->dev, "btusb%s", dev_name(&intf->dev));
> +       if (err)
> +               goto out_free_data;
> +
> +       err = device_register(&data->dev);
> +       if (err < 0)
> +               goto out_put_sysfs;
> +
>         hdev = hci_alloc_dev_priv(priv_size);
> -       if (!hdev)
> -               return -ENOMEM;
> +       if (!hdev) {
> +               err = -ENOMEM;
> +               goto out_free_sysfs;
> +       }
>
>         hdev->bus = HCI_USB;
>         hci_set_drvdata(hdev, data);
>
>         data->hdev = hdev;
>
> -       SET_HCIDEV_DEV(hdev, &intf->dev);
> +       SET_HCIDEV_DEV(hdev, &data->dev);
>
>         reset_gpio = gpiod_get_optional(&data->udev->dev, "reset",
>                                         GPIOD_OUT_LOW);
> @@ -3971,15 +4038,6 @@ static int btusb_probe(struct usb_interface *intf,
>                 hci_set_msft_opcode(hdev, 0xFD70);
>         }
>
> -       if (id->driver_info & BTUSB_AMP) {
> -               /* AMP controllers do not support SCO packets */
> -               data->isoc = NULL;
> -       } else {
> -               /* Interface orders are hardcoded in the specification */
> -               data->isoc = usb_ifnum_to_if(data->udev, ifnum_base + 1);
> -               data->isoc_ifnum = ifnum_base + 1;
> -       }
> -
>         if (IS_ENABLED(CONFIG_BT_HCIBTUSB_RTL) &&
>             (id->driver_info & BTUSB_REALTEK)) {
>                 btrtl_set_driver_name(hdev, btusb_driver.name);
> @@ -4012,9 +4070,6 @@ static int btusb_probe(struct usb_interface *intf,
>                         set_bit(HCI_QUIRK_FIXUP_BUFFER_SIZE, &hdev->quirks);
>         }
>
> -       if (id->driver_info & BTUSB_BROKEN_ISOC)
> -               data->isoc = NULL;
> -
>         if (id->driver_info & BTUSB_WIDEBAND_SPEECH)
>                 set_bit(HCI_QUIRK_WIDEBAND_SPEECH_SUPPORTED, &hdev->quirks);
>
> @@ -4067,10 +4122,6 @@ static int btusb_probe(struct usb_interface *intf,
>                                                  data->isoc, data);
>                 if (err < 0)
>                         goto out_free_dev;
> -
> -               err = device_create_file(&intf->dev, &dev_attr_isoc_alt);
> -               if (err)
> -                       goto out_free_dev;
>         }
>
>         if (IS_ENABLED(CONFIG_BT_HCIBTUSB_BCM) && data->diag) {
> @@ -4101,6 +4152,16 @@ static int btusb_probe(struct usb_interface *intf,
>         if (data->reset_gpio)
>                 gpiod_put(data->reset_gpio);
>         hci_free_dev(hdev);
> +
> +out_free_sysfs:
> +       device_del(&data->dev);
> +
> +out_put_sysfs:
> +       put_device(&data->dev);
> +       return err;
> +
> +out_free_data:
> +       kfree(data);
>         return err;
>  }
>
> @@ -4117,10 +4178,8 @@ static void btusb_disconnect(struct usb_interface *intf)
>         hdev = data->hdev;
>         usb_set_intfdata(data->intf, NULL);
>
> -       if (data->isoc) {
> -               device_remove_file(&intf->dev, &dev_attr_isoc_alt);
> +       if (data->isoc)
>                 usb_set_intfdata(data->isoc, NULL);
> -       }
>
>         if (data->diag)
>                 usb_set_intfdata(data->diag, NULL);
> @@ -4152,6 +4211,7 @@ static void btusb_disconnect(struct usb_interface *intf)
>                 gpiod_put(data->reset_gpio);
>
>         hci_free_dev(hdev);
> +       device_unregister(&data->dev);
>  }
>
>  #ifdef CONFIG_PM
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index 05919848ea95..776dd6183509 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -1843,6 +1843,7 @@ int hci_get_adv_monitor_offload_ext(struct hci_dev *hdev);
>
>  void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb);
>
> +extern const struct class bt_class;
>  void hci_init_sysfs(struct hci_dev *hdev);
>  void hci_conn_init_sysfs(struct hci_conn *conn);
>  void hci_conn_add_sysfs(struct hci_conn *conn);
> diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c
> index 041ce9adc378..f8c2c1c3e887 100644
> --- a/net/bluetooth/hci_sysfs.c
> +++ b/net/bluetooth/hci_sysfs.c
> @@ -6,9 +6,10 @@
>  #include <net/bluetooth/bluetooth.h>
>  #include <net/bluetooth/hci_core.h>
>
> -static const struct class bt_class = {
> +const struct class bt_class = {
>         .name = "bluetooth",
>  };
> +EXPORT_SYMBOL_GPL(bt_class);
>
>  static void bt_link_release(struct device *dev)
>  {
> --
> 2.48.1.601.g30ceb7b040-goog
>

Hi Luiz and Greg,

Friendly ping for review, thanks.

Greg KH Feb. 21, 2025, 5:45 a.m. UTC | #2

On Fri, Feb 21, 2025 at 09:42:16AM +0800, Hsin-chen Chuang wrote:
> On Wed, Feb 19, 2025 at 10:03 PM Hsin-chen Chuang <[e-mail]> wrote:

<snip>

> Hi Luiz and Greg,
> 
> Friendly ping for review, thanks.

A review in less than 2 days?  Please be reasonable here, remember, many
of us get 1000+ emails a day to deal with.

To help reduce our load, take the time and review other patches on the
mailing lists.  You are doing that, right?  If not, why not?

patience please.

greg k-h

Hsin-chen Chuang Feb. 21, 2025, 5:56 a.m. UTC | #3

On Fri, Feb 21, 2025 at 1:47 PM Greg KH <[e-mail]> wrote:
>
> On Fri, Feb 21, 2025 at 09:42:16AM +0800, Hsin-chen Chuang wrote:
> > On Wed, Feb 19, 2025 at 10:03 PM Hsin-chen Chuang <[e-mail]> wrote:
>
> <snip>
>
> > Hi Luiz and Greg,
> >
> > Friendly ping for review, thanks.
>
> A review in less than 2 days?  Please be reasonable here, remember, many
> of us get 1000+ emails a day to deal with.
>
> To help reduce our load, take the time and review other patches on the
> mailing lists.  You are doing that, right?  If not, why not?
>
> patience please.
>
> greg k-h

Got it. Take your time and thank you

Patch

diff --git a/Documentation/ABI/stable/sysfs-class-bluetooth b/Documentation/ABI/stable/sysfs-class-bluetooth
index 36be02471174..c1024c7c4634 100644
--- a/Documentation/ABI/stable/sysfs-class-bluetooth
+++ b/Documentation/ABI/stable/sysfs-class-bluetooth
@@ -7,3 +7,16 @@  Description: 	This write-only attribute allows users to trigger the vendor reset
 		The reset may or may not be done through the device transport
 		(e.g., UART/USB), and can also be done through an out-of-band
 		approach such as GPIO.
+
+What:		/sys/class/bluetooth/btusb<usb-intf>/isoc_alt
+Date:		13-Feb-2025
+KernelVersion:	6.13
+Contact:	[e-mail]
+Description:	This attribute allows users to configure the USB Alternate setting
+		for the specific HCI device. Reading this attribute returns the
+		current setting, and writing any supported numbers would change
+		the setting. See the USB Alternate setting definition in Bluetooth
+		core spec 5, vol 4, part B, table 2.1.
+		If the HCI device is not yet init-ed, the write fails with -ENODEV.
+		If the data is not a valid number, the write fails with -EINVAL.
+		The other failures are vendor specific.
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index de3fa725d210..495f0ceba95d 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -920,6 +920,8 @@  struct btusb_data {
 	int oob_wake_irq;   /* irq for out-of-band wake-on-bt */
 
 	struct qca_dump_info qca_dump;
+
+	struct device dev;
 };
 
 static void btusb_reset(struct hci_dev *hdev)
@@ -3682,7 +3684,7 @@  static ssize_t isoc_alt_show(struct device *dev,
 			     struct device_attribute *attr,
 			     char *buf)
 {
-	struct btusb_data *data = dev_get_drvdata(dev);
+	struct btusb_data *data = container_of(dev, struct btusb_data, dev);
 
 	return sysfs_emit(buf, "%d\n", data->isoc_altsetting);
 }
@@ -3691,10 +3693,13 @@  static ssize_t isoc_alt_store(struct device *dev,
 			      struct device_attribute *attr,
 			      const char *buf, size_t count)
 {
-	struct btusb_data *data = dev_get_drvdata(dev);
+	struct btusb_data *data = container_of(dev, struct btusb_data, dev);
 	int alt;
 	int ret;
 
+	if (!data->hdev)
+		return -ENODEV;
+
 	if (kstrtoint(buf, 10, &alt))
 		return -EINVAL;
 
@@ -3704,6 +3709,36 @@  static ssize_t isoc_alt_store(struct device *dev,
 
 static DEVICE_ATTR_RW(isoc_alt);
 
+static struct attribute *btusb_sysfs_attrs[] = {
+	NULL,
+};
+ATTRIBUTE_GROUPS(btusb_sysfs);
+
+static void btusb_sysfs_release(struct device *dev)
+{
+	struct btusb_data *data = container_of(dev, struct btusb_data, dev);
+
+	kfree(data);
+}
+
+static const struct device_type btusb_sysfs = {
+	.name    = "btusb",
+	.release = btusb_sysfs_release,
+	.groups  = btusb_sysfs_groups,
+};
+
+static struct attribute *btusb_sysfs_isoc_alt_attrs[] = {
+	&dev_attr_isoc_alt.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(btusb_sysfs_isoc_alt);
+
+static const struct device_type btusb_sysfs_isoc_alt = {
+	.name    = "btusb",
+	.release = btusb_sysfs_release,
+	.groups  = btusb_sysfs_isoc_alt_groups,
+};
+
 static int btusb_probe(struct usb_interface *intf,
 		       const struct usb_device_id *id)
 {
@@ -3745,7 +3780,7 @@  static int btusb_probe(struct usb_interface *intf,
 			return -ENODEV;
 	}
 
-	data = devm_kzalloc(&intf->dev, sizeof(*data), GFP_KERNEL);
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
@@ -3768,8 +3803,10 @@  static int btusb_probe(struct usb_interface *intf,
 		}
 	}
 
-	if (!data->intr_ep || !data->bulk_tx_ep || !data->bulk_rx_ep)
-		return -ENODEV;
+	if (!data->intr_ep || !data->bulk_tx_ep || !data->bulk_rx_ep) {
+		err = -ENODEV;
+		goto out_free_data;
+	}
 
 	if (id->driver_info & BTUSB_AMP) {
 		data->cmdreq_type = USB_TYPE_CLASS | 0x01;
@@ -3823,16 +3860,46 @@  static int btusb_probe(struct usb_interface *intf,
 
 	data->recv_acl = hci_recv_frame;
 
+	if (id->driver_info & BTUSB_AMP) {
+		/* AMP controllers do not support SCO packets */
+		data->isoc = NULL;
+	} else {
+		/* Interface orders are hardcoded in the specification */
+		data->isoc = usb_ifnum_to_if(data->udev, ifnum_base + 1);
+		data->isoc_ifnum = ifnum_base + 1;
+	}
+
+	if (id->driver_info & BTUSB_BROKEN_ISOC)
+		data->isoc = NULL;
+
+	/* Init a dev for btusb. The attr depends on the support of isoc. */
+	if (data->isoc)
+		data->dev.type = &btusb_sysfs_isoc_alt;
+	else
+		data->dev.type = &btusb_sysfs;
+	data->dev.class = &bt_class;
+	data->dev.parent = &intf->dev;
+
+	err = dev_set_name(&data->dev, "btusb%s", dev_name(&intf->dev));
+	if (err)
+		goto out_free_data;
+
+	err = device_register(&data->dev);
+	if (err < 0)
+		goto out_put_sysfs;
+
 	hdev = hci_alloc_dev_priv(priv_size);
-	if (!hdev)
-		return -ENOMEM;
+	if (!hdev) {
+		err = -ENOMEM;
+		goto out_free_sysfs;
+	}
 
 	hdev->bus = HCI_USB;
 	hci_set_drvdata(hdev, data);
 
 	data->hdev = hdev;
 
-	SET_HCIDEV_DEV(hdev, &intf->dev);
+	SET_HCIDEV_DEV(hdev, &data->dev);
 
 	reset_gpio = gpiod_get_optional(&data->udev->dev, "reset",
 					GPIOD_OUT_LOW);
@@ -3971,15 +4038,6 @@  static int btusb_probe(struct usb_interface *intf,
 		hci_set_msft_opcode(hdev, 0xFD70);
 	}
 
-	if (id->driver_info & BTUSB_AMP) {
-		/* AMP controllers do not support SCO packets */
-		data->isoc = NULL;
-	} else {
-		/* Interface orders are hardcoded in the specification */
-		data->isoc = usb_ifnum_to_if(data->udev, ifnum_base + 1);
-		data->isoc_ifnum = ifnum_base + 1;
-	}
-
 	if (IS_ENABLED(CONFIG_BT_HCIBTUSB_RTL) &&
 	    (id->driver_info & BTUSB_REALTEK)) {
 		btrtl_set_driver_name(hdev, btusb_driver.name);
@@ -4012,9 +4070,6 @@  static int btusb_probe(struct usb_interface *intf,
 			set_bit(HCI_QUIRK_FIXUP_BUFFER_SIZE, &hdev->quirks);
 	}
 
-	if (id->driver_info & BTUSB_BROKEN_ISOC)
-		data->isoc = NULL;
-
 	if (id->driver_info & BTUSB_WIDEBAND_SPEECH)
 		set_bit(HCI_QUIRK_WIDEBAND_SPEECH_SUPPORTED, &hdev->quirks);
 
@@ -4067,10 +4122,6 @@  static int btusb_probe(struct usb_interface *intf,
 						 data->isoc, data);
 		if (err < 0)
 			goto out_free_dev;
-
-		err = device_create_file(&intf->dev, &dev_attr_isoc_alt);
-		if (err)
-			goto out_free_dev;
 	}
 
 	if (IS_ENABLED(CONFIG_BT_HCIBTUSB_BCM) && data->diag) {
@@ -4101,6 +4152,16 @@  static int btusb_probe(struct usb_interface *intf,
 	if (data->reset_gpio)
 		gpiod_put(data->reset_gpio);
 	hci_free_dev(hdev);
+
+out_free_sysfs:
+	device_del(&data->dev);
+
+out_put_sysfs:
+	put_device(&data->dev);
+	return err;
+
+out_free_data:
+	kfree(data);
 	return err;
 }
 
@@ -4117,10 +4178,8 @@  static void btusb_disconnect(struct usb_interface *intf)
 	hdev = data->hdev;
 	usb_set_intfdata(data->intf, NULL);
 
-	if (data->isoc) {
-		device_remove_file(&intf->dev, &dev_attr_isoc_alt);
+	if (data->isoc)
 		usb_set_intfdata(data->isoc, NULL);
-	}
 
 	if (data->diag)
 		usb_set_intfdata(data->diag, NULL);
@@ -4152,6 +4211,7 @@  static void btusb_disconnect(struct usb_interface *intf)
 		gpiod_put(data->reset_gpio);
 
 	hci_free_dev(hdev);
+	device_unregister(&data->dev);
 }
 
 #ifdef CONFIG_PM
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 05919848ea95..776dd6183509 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1843,6 +1843,7 @@  int hci_get_adv_monitor_offload_ext(struct hci_dev *hdev);
 
 void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb);
 
+extern const struct class bt_class;
 void hci_init_sysfs(struct hci_dev *hdev);
 void hci_conn_init_sysfs(struct hci_conn *conn);
 void hci_conn_add_sysfs(struct hci_conn *conn);
diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c
index 041ce9adc378..f8c2c1c3e887 100644
--- a/net/bluetooth/hci_sysfs.c
+++ b/net/bluetooth/hci_sysfs.c
@@ -6,9 +6,10 @@ 
 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>
 
-static const struct class bt_class = {
+const struct class bt_class = {
 	.name = "bluetooth",
 };
+EXPORT_SYMBOL_GPL(bt_class);
 
 static void bt_link_release(struct device *dev)
 {