From 8167c9a375ccceed19048ad9d68cb2d02ed276e0 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Thu, 9 Sep 2021 12:13:36 +0300
Subject: [PATCH] iio: ssp_sensors: add more range checking in ssp_parse_dataframe()
Git-commit: 8167c9a375ccceed19048ad9d68cb2d02ed276e0
Patch-mainline: v5.15-rc6
References: git-fixes stable-5.14.14

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/iio/common/ssp_sensors/ssp_spi.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/common/ssp_sensors/ssp_spi.c b/drivers/iio/common/ssp_sensors/ssp_spi.c
index 77449b4f3df5..769bd9280524 100644
--- 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 ssp_data *data, char *dataframe, int len)
 	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 ssp_data *data, char *dataframe, int len)
 
 			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 ssp_data *data, char *dataframe, int len)
 			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,
-- 
2.26.2