iio: health: afe4403: Fix oob read in afe4403_read_raw

[ Upstream commit 58143c1ed5 ]

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: b36e825764 ("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>
This commit is contained in:
Wei Yongjun 2022-11-07 15:19:46 +00:00 committed by Greg Kroah-Hartman
parent ebdca90efb
commit e7e76a77aa

View File

@ -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;