Re: [PATCH 6/9] iio: adc: ti-adc128s052: validate SPI match data

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 26 Sep 2026 02:15:06 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> On Fri, 25 Sep 2026 20:57:44 +0800
> Jiale Yao <yaojiale02@163.com> wrote:
> 
> > SPI driver_override allows a device to bind to this driver without
> > matching either the firmware tables or SPI device ID table. In that
> > case, spi_get_device_match_data() returns NULL.
> > 
> > adc128_probe() also obtains the IIO device name by dereferencing the
> > result of spi_get_device_id(), which is NULL on the same override path.
> > The probe can therefore crash before it reaches the match data access.
> > 
> > Commit 572a00852635 ("iio: dac: ad5686: missing NULL check on match
> > data") fixed the same driver_override issue in another SPI driver.
> > Reject devices without match data and use the always available SPI
> > modalias for the IIO device name.  
> 
> Why this change?  The name is clearly encoded in a place that makes
> it readily available and verifiably the right thing in a way that
> spi->modalias does not.
> There isn't any reason the IIO name would always match that even it
> happens to do so here.

Actually - ignore that, I misread this and assumed the code
was different from what was actually there.

Drivers shouldn't be using spi_get_device_id(spi)->name but
I'm not sure modalias is any better.

I'm out of time for now, so will revisit this in a day or so.

> 
> 
> > 
> > Fixes: d5f0da0c6972 ("iio: adc: ti-adc128s052: Switch to use spi_get_device_match_data()")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Jiale Yao <yaojiale02@163.com>
> > ---
> >  drivers/iio/adc/ti-adc128s052.c | 8 +++++---
> >  1 file changed, 5 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/iio/adc/ti-adc128s052.c b/drivers/iio/adc/ti-adc128s052.c
> > index 1899813c1aee..f9a995ff403e 100644
> > --- a/drivers/iio/adc/ti-adc128s052.c
> > +++ b/drivers/iio/adc/ti-adc128s052.c
> > @@ -195,12 +195,14 @@ static int adc128_probe(struct spi_device *spi)
> >  	adc = iio_priv(indio_dev);
> >  	adc->spi = spi;
> >  
> > -	indio_dev->name = spi_get_device_id(spi)->name;
> > +	config = spi_get_device_match_data(spi);
> > +	if (!config)
> > +		return -ENODATA;
> > +
> > +	indio_dev->name = spi->modalias;
> >  	indio_dev->modes = INDIO_DIRECT_MODE;
> >  	indio_dev->info = &adc128_info;
> >  
> > -	config = spi_get_device_match_data(spi);
> > -
> >  	indio_dev->channels = config->channels;
> >  	indio_dev->num_channels = config->num_channels;
> >    
> 
>