[PATCH 5.10 059/103] iio: ssp_sensors: add more range checking in ssp_parse_dataframe()

Greg Kroah-Hartman
2021-10-18T13:43:43Z

From: Dan Carpenter <dan.carpenter@oracle.com>

commit 8167c9a375ccceed19048ad9d68cb2d02ed276e0 upstream.

The "idx" is validated at the start of the loop but it gets incremented
during the iteration so it needs to be checked again.

Fixes: 50dd64d57eee ("iio: common: ssp_sensors: Add sensorhub driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20210909091336.GA26312@kili
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/iio/common/ssp_sensors/ssp_spi.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

--- a/drivers/iio/common/ssp_sensors/ssp_spi.c
+++ b/drivers/iio/common/ssp_sensors/ssp_spi.c
@@ -273,6 +273,8 @@ static int ssp_parse_dataframe(struct ss
for (idx = 0; idx < len;) {
switch (dataframe[idx++]) {
case SSP_MSG2AP_INST_BYPASS_DATA:
+ if (idx >= len)
+ return -EPROTO;
sd = dataframe[idx++];
if (sd < 0 || sd >= SSP_SENSOR_MAX) {
dev_err(SSP_DEV,
@@ -282,10 +284,13 @@ static int ssp_parse_dataframe(struct ss

if (indio_devs[sd]) {
spd = iio_priv(indio_devs[sd]);
- if (spd->process_data)
+ if (spd->process_data) {
+ if (idx >= len)
+ return -EPROTO;
spd->process_data(indio_devs[sd],
&dataframe[idx],
data->timestamp);
+ }
} else {
dev_err(SSP_DEV, "no client for frame\n");
}
@@ -293,6 +298,8 @@ static int ssp_parse_dataframe(struct ss
idx += ssp_offset_map[sd];
break;
case SSP_MSG2AP_INST_DEBUG_DATA:
+ if (idx >= len)
+ return -EPROTO;
sd = ssp_print_mcu_debug(dataframe, &idx, len);
if (sd) {
dev_err(SSP_DEV,