Re: [PATCH] usb: gadget: Check bmAttributes only if configuration is valid

[Prashanth K <prashanth.k@oss.qualcomm.com>]

On 24-02-25 02:36 pm, Greg Kroah-Hartman wrote:
> On Mon, Feb 24, 2025 at 02:26:04PM +0530, Prashanth K wrote:
>> If the USB configuration is not valid, then avoid checking for
>> bmAttributes to prevent null pointer deference.
>>
>> Cc: stable@vger.kernel.org
>> Fixes: 40e89ff5750f ("usb: gadget: Set self-powered based on MaxPower and bmAttributes")
>> Signed-off-by: Prashanth K <prashanth.k@oss.qualcomm.com>
>> ---
>>  drivers/usb/gadget/composite.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
>> index 4bcf73bae761..869ad99afb48 100644
>> --- a/drivers/usb/gadget/composite.c
>> +++ b/drivers/usb/gadget/composite.c
>> @@ -1051,7 +1051,7 @@ static int set_config(struct usb_composite_dev *cdev,
>>  		usb_gadget_set_remote_wakeup(gadget, 0);
>>  done:
>>  	if (power > USB_SELF_POWER_VBUS_MAX_DRAW ||
>> -	    !(c->bmAttributes & USB_CONFIG_ATT_SELFPOWER))
>> +	    (c && !(c->bmAttributes & USB_CONFIG_ATT_SELFPOWER)))
>>  		usb_gadget_clear_selfpowered(gadget);
>>  	else
>>  		usb_gadget_set_selfpowered(gadget);
>> -- 
>> 2.25.1
>>
>>
> 
> Have you checked linux-next yet for this fix that was posted last week?
> Does that not resolve the issue for you?
> 
> thanks,
> 
> greg k-h

I hope you are mentioning this one -
https://lore.kernel.org/all/20250220120314.3614330-1-m.szyprowski@samsung.com/

The above patch fixes null pointer in composite_suspend(), I'm trying to
address a similar bug which is present in set_config(), it gets exposed
if the requested configuration is not present in cdev->configs.

Regards,
Prashanth K