Re: [PATCH] gpib: agilent_82357a: don't check a NULL serial string

[Joe Simmons-Talbott <joest@redhat.com>]

On Fri, Mar 27, 2026 at 11:38:49AM +0100, Dave Penkler wrote:
> On Thu, Mar 26, 2026 at 09:12:56AM -0400, Joe Simmons-Talbott wrote:
> > The agilent_82357a driver uses the USB device serial string for device
> > matching but does not verify that the string exists before passing it
> > to strcmp().
> > 
> > Verify that the device has a serial number before accessing it to avoid
> > triggering a NULL-pointer dereference with devices that don't provide
> > a serial number (iSerialNumber = 0).
> > 
> > Similar to commit aa79f996eb41 ("i2c: cp2615: fix serial string
> > NULL-deref at probe").
> > 
> > Found by Claude:sonnet-4.5
> > 
> > Signed-off-by: Joe Simmons-Talbott <joest@redhat.com>
> > ---
> >  drivers/gpib/agilent_82357a/agilent_82357a.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpib/agilent_82357a/agilent_82357a.c b/drivers/gpib/agilent_82357a/agilent_82357a.c
> > index e1349afbf933..da046ea40f11 100644
> > --- a/drivers/gpib/agilent_82357a/agilent_82357a.c
> > +++ b/drivers/gpib/agilent_82357a/agilent_82357a.c
> > @@ -1298,7 +1298,7 @@ static inline int agilent_82357a_device_match(struct usb_interface *interface,
> >  	if (gpib_match_device_path(&interface->dev, config->device_path) == 0)
> >  		return 0;
> >  	if (config->serial_number &&
> > -	    strcmp(usbdev->serial, config->serial_number) != 0)
> > +	    (!usbdev->serial || strcmp(usbdev->serial, config->serial_number) != 0))
> >  		return 0;
> >  
> >  	return 1;
> > -- 
> > 2.53.0
> > 
> Acked-by: Dave Penkler <dpenkler@gmail.com>
> 

+Greg

Hi Greg,

Sorry I neglected to include you on the original patch submission.  Are
you able to either take this patch or point me to the proper person?

Thanks,
Joe