On 17.03.2016 19:02, Jes Sorensen wrote:
> Jes Sorensen <Jes.Sorensen@xxxxxxxxxx> writes:
>> Xose Vazquez Perez <xose.vazquez@xxxxxxxxx> writes:
>>> Hi,
>>>
>>> If I do:
>>> # echo "0bda 8176" > /sys/bus/usb/drivers/rtl8xxxu/new_id
>>
>> Hi Xose,
>>
>> Yes please don't do that. The rtl8xxxu driver relies on the .driver_info
>> field in struct use_device_id to carry information for the different
>> types of devices. If you hot add a device like above, the driver will
>> fail because that field now contains a NULL pointer.
>>
>> I should probably add a check for it in the probe function, but it will
>> simply be there to spit out a warning that it doesn't work to hot add a
>> device like this.
>>
>> If you build it with CONFIG_RTL8XXXU_UNTESTED the 0bda:8176 should be
>> included in the device list.
>>
>> Cheers,
>> Jes
>
> Hi Xose,
>
> I added the following patch to my tree to avoid this.
>
> Cheers,
> Jes
>
> commit 9202f4947aac1d60084ee79c9b5294eb42ba59dc
> Author: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx>
> Date: Thu Mar 17 13:53:48 2016 -0400
>
> rtl8xxxu: Fix OOPS if user tries to add device via /sys
>
> This driver relies on driver_info in struct usb_device_id, hence
> adding a device via /sys/bus/usb/drivers/rtl8xxxu/new_id would result
> in a NULL pointer dereference.
>
> Instead print a message and return -ENODEV
>
> Reported-by: Xose Vazquez Perez <xose.vazquez@xxxxxxxxx>
> Signed-off-by: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx>
>
> diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.c
> index 8d893f4..55fc00e 100644
> --- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.c
> +++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu.c
> @@ -9671,6 +9671,15 @@ static int rtl8xxxu_probe(struct usb_interface *interface,
>
> udev = usb_get_dev(interface_to_usbdev(interface));
>
> + if (!id->driver_info) {
> + dev_warn(&udev->dev,
> + "rtl8xxxu relies on driver_info in struct usb_device_id.\n");
> + dev_warn(&udev->dev,
> + "Adding a device via /sys/bus/usb/drivers/rtl8xxxu/new_id is not supported!\n");
> + ret = -ENODEV;
> + goto exit;
> + }
> +
> switch (id->idVendor) {
> case USB_VENDOR_ID_REALTEK:
> switch(id->idProduct) {
>
Dynamic adding and removing a new device IDs to a USB device drivers
via /sys/bus/usb/drivers/.../[new_id|remove_id]
https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-bus-usb
is not supported only with rtl8xxxu?
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