The sorting in iio_gts_build_avail_time_table is not working as intended. It could result in an out-of-bounds access when the time is zero. Here are more details: 1. When the gts->itime_table[i].time_us is zero, e.g., the time sequence is `3, 0, 1`, the inner for-loop will not terminate and do out-of-bound writes. This is because once `times[j] > new`, the value `new` will be added in the current position and the `times[j]` will be moved to `j+1` position, which makes the if-condition always hold. Meanwhile, idx will be added one, making the loop keep running without termination and out-of-bound write. 2. If none of the gts->itime_table[i].time_us is zero, the elements will just be copied without being sorted as described in the comment "Sort times from all tables to one and remove duplicates". For more details, please refer to https://lore.kernel.org/all/6dd0d822-046c-4dd2-9532-79d7ab96ec05@xxxxxxxxx. Reported-by: Chenyuan Yang <chenyuan0y@xxxxxxxxx> Suggested-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx> Fixes: 38416c28e16890b52fdd5eb73479299ec3f062f3 ("iio: light: Add gain-time-scale helpers") Signed-off-by: Chenyuan Yang <chenyuan0y@xxxxxxxxx> --- diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c index 7653261d2dc2..61714a8d5717 100644 --- a/drivers/iio/industrialio-gts-helper.c +++ b/drivers/iio/industrialio-gts-helper.c @@ -375,7 +375,7 @@ static int iio_gts_build_avail_time_table(struct iio_gts *gts) for (i = gts->num_itime - 1; i >= 0; i--) { int new = gts->itime_table[i].time_us; - if (times[idx] < new) { + if (idx == 0 || times[idx - 1] < new) { times[idx++] = new; continue; } @@ -385,9 +385,10 @@ static int iio_gts_build_avail_time_table(struct iio_gts *gts) memmove(×[j + 1], ×[j], (idx - j) * sizeof(int)); times[j] = new; - idx++; + break; } } + idx++; } /* create a list of times formatted as list of IIO_VAL_INT_PLUS_MICRO */
