iio: imu: st_lsm6dsx: Avoid potential array overflow in st_lsm6dsx_set_odr()

The length of hw->settings->odr_table is 2 and ref_sensor->id is an enum
variable whose value is between 0 and 5.
However, the value ST_LSM6DSX_ID_MAX (i.e. 5) is not caught properly in
 switch (sensor->id) {

If ref_sensor->id is ST_LSM6DSX_ID_MAX, an array overflow will ocurrs in
function st_lsm6dsx_check_odr():
  odr_table = &sensor->hw->settings->odr_table[sensor->id];

and in function st_lsm6dsx_set_odr():
  reg = &hw->settings->odr_table[ref_sensor->id].reg;

To avoid this array overflow, handle ST_LSM6DSX_ID_GYRO explicitly and
return -EINVAL for the default case.

The enum value ST_LSM6DSX_ID_MAX is only present as an easy way to check
the limit and as such is never used, however this is not locally obvious.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Teng Qi <starmiku1207184332@gmail.com>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/20211011114003.976221-1-starmiku1207184332@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Teng Qi 2021-10-11 19:40:03 +08:00 committed by Jonathan Cameron
parent 77b91b1cbc
commit 94be878c88

View File

@ -1281,6 +1281,8 @@ st_lsm6dsx_set_odr(struct st_lsm6dsx_sensor *sensor, u32 req_odr)
int err;
switch (sensor->id) {
case ST_LSM6DSX_ID_GYRO:
break;
case ST_LSM6DSX_ID_EXT0:
case ST_LSM6DSX_ID_EXT1:
case ST_LSM6DSX_ID_EXT2:
@ -1306,8 +1308,8 @@ st_lsm6dsx_set_odr(struct st_lsm6dsx_sensor *sensor, u32 req_odr)
}
break;
}
default:
break;
default: /* should never occur */
return -EINVAL;
}
if (req_odr > 0) {