From: Wei Yongjun weiyongjun1@huawei.com
[ Upstream commit fc92d9e3de0b2d30a3ccc08048a5fad533e4672b ]
KASAN report out-of-bounds read as follows:
BUG: KASAN: global-out-of-bounds in afe4404_read_raw+0x2ce/0x380 Read of size 4 at addr ffffffffc00e4658 by task cat/278
Call Trace: afe4404_read_raw iio_read_channel_info dev_attr_show
The buggy address belongs to the variable: afe4404_channel_leds+0x18/0xffffffffffffe9c0
This issue can be reproduce by singe command:
$ cat /sys/bus/i2c/devices/0-0058/iio:device0/in_intensity6_raw
The array size of afe4404_channel_leds and afe4404_channel_offdacs are less than channels, so access with chan->address cause OOB read in afe4404_[read|write]_raw. Fix it by moving access before use them.
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/20221107152010.95937-1-weiyongjun@huaweicloud.com Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/iio/health/afe4404.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/health/afe4404.c b/drivers/iio/health/afe4404.c index 5e256b11ac87..29a906411bd8 100644 --- a/drivers/iio/health/afe4404.c +++ b/drivers/iio/health/afe4404.c @@ -258,20 +258,20 @@ static int afe4404_read_raw(struct iio_dev *indio_dev, int *val, int *val2, long mask) { struct afe4404_data *afe = iio_priv(indio_dev); - unsigned int value_reg = afe4404_channel_values[chan->address]; - unsigned int led_field = afe4404_channel_leds[chan->address]; - unsigned int offdac_field = afe4404_channel_offdacs[chan->address]; + unsigned int value_reg, led_field, offdac_field; int ret;
switch (chan->type) { case IIO_INTENSITY: switch (mask) { case IIO_CHAN_INFO_RAW: + value_reg = afe4404_channel_values[chan->address]; ret = regmap_read(afe->regmap, value_reg, val); if (ret) return ret; return IIO_VAL_INT; case IIO_CHAN_INFO_OFFSET: + offdac_field = afe4404_channel_offdacs[chan->address]; ret = regmap_field_read(afe->fields[offdac_field], val); if (ret) return ret; @@ -281,6 +281,7 @@ static int afe4404_read_raw(struct iio_dev *indio_dev, case IIO_CURRENT: switch (mask) { case IIO_CHAN_INFO_RAW: + led_field = afe4404_channel_leds[chan->address]; ret = regmap_field_read(afe->fields[led_field], val); if (ret) return ret; @@ -303,19 +304,20 @@ static int afe4404_write_raw(struct iio_dev *indio_dev, int val, int val2, long mask) { struct afe4404_data *afe = iio_priv(indio_dev); - unsigned int led_field = afe4404_channel_leds[chan->address]; - unsigned int offdac_field = afe4404_channel_offdacs[chan->address]; + unsigned int led_field, offdac_field;
switch (chan->type) { case IIO_INTENSITY: switch (mask) { case IIO_CHAN_INFO_OFFSET: + offdac_field = afe4404_channel_offdacs[chan->address]; return regmap_field_write(afe->fields[offdac_field], val); } break; case IIO_CURRENT: switch (mask) { case IIO_CHAN_INFO_RAW: + led_field = afe4404_channel_leds[chan->address]; return regmap_field_write(afe->fields[led_field], val); } break;