Commit dd6183e4 authored by Ethan Tidmore's avatar Ethan Tidmore Committed by Jonathan Cameron
Browse files

iio: adc: ad7768-1: Fix ERR_PTR dereference in ad7768_fill_scale_tbl 



The function iio_get_current_scan_type() can return an error pointer,
the return value scan_type is not checked for this and immediately
dereferenced which can cause a kernel panic.

Add check for IS_ERR() and propagate the error back.

Fixes: ff085189 ("iio: adc: ad7768-1: add support for ADAQ776x-1 ADC Family")
Reported-by: default avatarkernel test robot <lkp@intel.com>
Reported-by: default avatarDan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/202602051234.5gArzLyZ-lkp@intel.com/


Signed-off-by: default avatarEthan Tidmore <ethantidmore06@gmail.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent c3914ce1

drivers/iio/adc/ad7768-1.c

+11 −2
Original line number Diff line number Diff line
@@ -531,7 +531,7 @@ static int ad7768_reg_access(struct iio_dev *indio_dev, 
	return ret;

}



static void ad7768_fill_scale_tbl(struct iio_dev *dev)

static int ad7768_fill_scale_tbl(struct iio_dev *dev)

{

	struct ad7768_state *st = iio_priv(dev);

	const struct iio_scan_type *scan_type;
@@ -541,6 +541,11 @@ static void ad7768_fill_scale_tbl(struct iio_dev *dev) 
	u64 tmp2;



	scan_type = iio_get_current_scan_type(dev, &dev->channels[0]);

	if (IS_ERR(scan_type)) {

		dev_err(&st->spi->dev, "Failed to get scan type.\n");

		return PTR_ERR(scan_type);

	}



	if (scan_type->sign == 's')

		val2 = scan_type->realbits - 1;

	else
@@ -565,6 +570,8 @@ static void ad7768_fill_scale_tbl(struct iio_dev *dev) 
		st->scale_tbl[i][0] = tmp0; /* Integer part */

		st->scale_tbl[i][1] = abs(tmp1); /* Fractional part */

	}



	return 0;

}



static int ad7768_set_sinc3_dec_rate(struct ad7768_state *st,
@@ -669,7 +676,9 @@ static int ad7768_configure_dig_fil(struct iio_dev *dev, 
	}



	/* Update scale table: scale values vary according to the precision */

	ad7768_fill_scale_tbl(dev);

	ret = ad7768_fill_scale_tbl(dev);

	if (ret)

		return ret;



	ad7768_fill_samp_freq_tbl(st);