iio: health: afe4403: Fix oob read in afe4403_read_raw
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:
b36e8257641a ("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>