Commit 2d6a4370 authored Nov 07, 2022 by Wei Yongjun Committed by Greg Kroah-Hartman Dec 08, 2022

iio: health: afe4403: Fix oob read in afe4403_read_raw



[ Upstream commit 58143c1ed5882c138a3cd2251a336fc8755f23d9 ]

KASAN report out-of-bounds read as follows:

BUG: KASAN: global-out-of-bounds in afe4403_read_raw+0x42e/0x4c0
Read of size 4 at addr ffffffffc02ac638 by task cat/279

Call Trace:
 afe4403_read_raw
 iio_read_channel_info
 dev_attr_show

The buggy address belongs to the variable:
 afe4403_channel_leds+0x18/0xffffffffffffe9e0

This issue can be reproduced by singe command:

 $ cat /sys/bus/spi/devices/spi0.0/iio\:device0/in_intensity6_raw

The array size of afe4403_channel_leds is less than channels, so access
with chan->address cause OOB read in afe4403_read_raw. Fix it by moving
access before use it.

Fixes: b36e8257 ("iio: health/afe440x: Use regmap fields")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Andrew Davis <afd@ti.com>
Link: https://lore.kernel.org/r/20221107151946.89260-1-weiyongjun@huaweicloud.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 8eb912af

drivers/iio/health/afe4403.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -245,14 +245,14 @@ static int afe4403_read_raw(struct iio_dev *indio_dev,
		int val, int val2, long mask)
		{
		struct afe4403_data *afe = iio_priv(indio_dev);
		unsigned int reg = afe4403_channel_values[chan->address];
		unsigned int field = afe4403_channel_leds[chan->address];
		unsigned int reg, field;
		int ret;

		switch (chan->type) {
		case IIO_INTENSITY:
		switch (mask) {
		case IIO_CHAN_INFO_RAW:
		reg = afe4403_channel_values[chan->address];
		ret = afe4403_read(afe, reg, val);
		if (ret)
		return ret;
		@@ -262,6 +262,7 @@ static int afe4403_read_raw(struct iio_dev *indio_dev,
		case IIO_CURRENT:
		switch (mask) {
		case IIO_CHAN_INFO_RAW:
		field = afe4403_channel_leds[chan->address];
		ret = regmap_field_read(afe->fields[field], val);
		if (ret)
		return ret;