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

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

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

On Mon, Feb 24, 2025 at 02:53:59PM +0530, Prashanth K wrote:
> 
> 
> 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/

Yes.

> 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.

Ah, missed that, sorry.  I'll go queue this up too.

thanks,

greg k-h