Re: [PATCH v2] iio: hmc5843: fix potential NULL pointer dereferences

[Jonathan Cameron <jic23@jic23.retrosnub.co.uk>]

On Sun, 24 Mar 2019 10:48:56 +0000
Jonathan Cameron <jic23@kernel.org> wrote:

> On Sat, 16 Mar 2019 17:08:33 -0500
> Kangjie Lu <kjlu@umn.edu> wrote:
> 
> > devm_regmap_init_i2c may fail and return NULL. The fix returns
> > the error when it fails.
> > 
> > Signed-off-by: Kangjie Lu <kjlu@umn.edu>  
> Applied to the togreg branch of iio.git and pushed out as testing
> for the autobuilders to play with it.
> Thanks.

Ah, how the eye jumps over the obvious...

Good thing this one was caught by build tests.

See below.

I've fixed up in the tree.

Jonathan

> 
> Jonathan
> 
> > ---
> > V2: fix the two together
> > ---
> >  drivers/iio/magnetometer/hmc5843_i2c.c | 7 ++++++-
> >  drivers/iio/magnetometer/hmc5843_spi.c | 7 ++++++-
> >  2 files changed, 12 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/iio/magnetometer/hmc5843_i2c.c b/drivers/iio/magnetometer/hmc5843_i2c.c
> > index 3de7f4426ac4..86abba5827a2 100644
> > --- a/drivers/iio/magnetometer/hmc5843_i2c.c
> > +++ b/drivers/iio/magnetometer/hmc5843_i2c.c
> > @@ -58,8 +58,13 @@ static const struct regmap_config hmc5843_i2c_regmap_config = {
> >  static int hmc5843_i2c_probe(struct i2c_client *cli,
> >  			     const struct i2c_device_id *id)
> >  {
> > +	struct regmap *regmap = devm_regmap_init_i2c(cli,
> > +			&hmc5843_i2c_regmap_config);
> > +	if (IS_ERR(regmap))
> > +		return PTR_ERR(regmap);
> > +
> >  	return hmc5843_common_probe(&cli->dev,
> > -			devm_regmap_init_i2c(cli, &hmc5843_i2c_regmap_config),
> > +			regmap,
> >  			id->driver_data, id->name);
> >  }
> >  
> > diff --git a/drivers/iio/magnetometer/hmc5843_spi.c b/drivers/iio/magnetometer/hmc5843_spi.c
> > index 535f03a70d63..8355713651d4 100644
> > --- a/drivers/iio/magnetometer/hmc5843_spi.c
> > +++ b/drivers/iio/magnetometer/hmc5843_spi.c
> > @@ -58,6 +58,7 @@ static const struct regmap_config hmc5843_spi_regmap_config = {
> >  static int hmc5843_spi_probe(struct spi_device *spi)
> >  {
> >  	int ret;
> > +	struct regmap *regmap;
> >  	const struct spi_device_id *id = spi_get_device_id(spi);
> >  
> >  	spi->mode = SPI_MODE_3;
> > @@ -67,8 +68,12 @@ static int hmc5843_spi_probe(struct spi_device *spi)
> >  	if (ret)
> >  		return ret;
> >  
> > +	regmap = devm_regmap_init(spi, &hmc5843_spi_regmap_config);

devm_regmap_init_spi


> > +	if (IS_ERR(regmap))
> > +		return PTR_ERR(devm_regmap);

It's called regmap.

> > +
> >  	return hmc5843_common_probe(&spi->dev,
> > -			devm_regmap_init_spi(spi, &hmc5843_spi_regmap_config),
> > +			regmap,
> >  			id->driver_data, id->name);
> >  }
> >    
>