On Mon, 7 Nov 2022 15:19:46 +0000
Wei Yongjun <weiyongjun@xxxxxxxxxxxxxxx> wrote:
> From: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Acked-by: Andrew Davis <afd@xxxxxx>
Applied to the fixes-togreg branch of iio.git.
Thanks,
Jonathan
> ---
> v2 -> v3: re-format backtraces
> v1 -> v2: also moved 'reg' to right before we use it
> added Acked-by
>
> drivers/iio/health/afe4403.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/health/afe4403.c b/drivers/iio/health/afe4403.c
> index 3bb4028c5d74..df3bc5c3d378 100644
> --- a/drivers/iio/health/afe4403.c
> +++ b/drivers/iio/health/afe4403.c
> @@ -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;
