From: Gwendal Grignou <gwendal@xxxxxxxxxxxx> commit fc948409ccc1e8afe8655cee77c686eedbfbee60 upstream. Check input to be sure it matches Semtech sx9310 specification and can fit into debounce register. Compare argument writen to thresh_.._period with read from same sysfs attribute: Before: Afer: write | read write | read -1 | 8 -1 fails: -EINVAL 0 | 8 0 | 0 1 | 0 1 | 0 2..15 | 2^log2(N) 2..15 | 2^log2(N) 16 | 0 >= 16 fails: -EINVAL Fixes: 1b6872015f0b ("iio: sx9310: Support setting debounce values") Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210331182222.219533-1-gwendal@xxxxxxxxxxxx Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iio/proximity/sx9310.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/drivers/iio/proximity/sx9310.c +++ b/drivers/iio/proximity/sx9310.c @@ -763,7 +763,11 @@ static int sx9310_write_far_debounce(str int ret; unsigned int regval; - val = ilog2(val); + if (val > 0) + val = ilog2(val); + if (!FIELD_FIT(SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_MASK, val)) + return -EINVAL; + regval = FIELD_PREP(SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_MASK, val); mutex_lock(&data->mutex); @@ -780,7 +784,11 @@ static int sx9310_write_close_debounce(s int ret; unsigned int regval; - val = ilog2(val); + if (val > 0) + val = ilog2(val); + if (!FIELD_FIT(SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_MASK, val)) + return -EINVAL; + regval = FIELD_PREP(SX9310_REG_PROX_CTRL10_CLOSE_DEBOUNCE_MASK, val); mutex_lock(&data->mutex);