On Tue, 9 Nov 2021 17:16:24 -0500 Sasha Levin sashal@kernel.org wrote:
From: Teng Qi starmiku1207184332@gmail.com
[ Upstream commit 94be878c882d8d784ff44c639bf55f3b029f85af ]
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.c... Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Sasha Levin sashal@kernel.org
This is really just noise for stable. There wasn't a bug here though the change is doing some hardening and improving local readability by saving anyone having to confirm it can't occur by looking at the enum values.
I don't mind it going into stable though if others feel it's worthwhile.
Jonathan
drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c index db45f1fc0b817..8dbf744c5651f 100644 --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c @@ -1279,6 +1279,8 @@ st_lsm6dsx_set_odr(struct st_lsm6dsx_sensor *sensor, u32 req_odr) int err; switch (sensor->id) {
- case ST_LSM6DSX_ID_GYRO:
break;@@ -1304,8 +1306,8 @@ 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) {