From: Wei Yongjun weiyongjun1@huawei.com
[ 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: 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 Signed-off-by: Sasha Levin sashal@kernel.org --- 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 38734e4ce360..82d01ac36128 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;