iio: filter: admv8818: close potential out-of-bounds read in __admv8818_read_[h|l]pf_freq()

ADMV8818_SW_IN_WR0_MSK and ADMV8818_SW_OUT_WR0_MSK have 3 bits,
which means a length of 8, but freq_range_hpf and freq_range_lpf
array size is 4, may end up reading 4 elements beyond the end of
those arrays.

Check value first before access freq_range_hpf and freq_range_lpf
to harden against the hardware allowing out of range values.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Link: https://lore.kernel.org/r/20220922115848.1800021-1-weiyongjun@huaweicloud.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Wei Yongjun 2022-09-22 11:58:48 +00:00 committed by Jonathan Cameron
parent 8cf5f03291
commit 3f4033a811

View file

@ -265,7 +265,7 @@ static int __admv8818_read_hpf_freq(struct admv8818_state *st, u64 *hpf_freq)
return ret;
hpf_band = FIELD_GET(ADMV8818_SW_IN_WR0_MSK, data);
if (!hpf_band) {
if (!hpf_band || hpf_band > 4) {
*hpf_freq = 0;
return ret;
}
@ -303,7 +303,7 @@ static int __admv8818_read_lpf_freq(struct admv8818_state *st, u64 *lpf_freq)
return ret;
lpf_band = FIELD_GET(ADMV8818_SW_OUT_WR0_MSK, data);
if (!lpf_band) {
if (!lpf_band || lpf_band > 4) {
*lpf_freq = 0;
return ret;
}