On Mon, Oct 04, 2021 at 09:27:35PM +0200, Marijn Suijten wrote:
> The strings passed in DT may possibly cause out-of-bounds register
> accesses and should be validated before use.
>
> Fixes: 775d2ffb4af6 ("backlight: qcom-wled: Restructure the driver for WLED3")
The first half of this patch actually fixes patch 1 from this patch set.
It would be better to move that code there.
Daniel.
> Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx>
> ---
> drivers/video/backlight/qcom-wled.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index 29910e603c42..27e8949c7922 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> @@ -1526,6 +1526,12 @@ static int wled_configure(struct wled *wled)
> "qcom,enabled-strings",
> sizeof(u32));
> if (string_len > 0) {
> + if (string_len > wled->max_string_count) {
> + dev_err(dev, "Cannot have more than %d strings\n",
> + wled->max_string_count);
> + return -EINVAL;
> + }
> +
> rc = of_property_read_u32_array(dev->of_node,
> "qcom,enabled-strings",
> wled->cfg.enabled_strings,
> @@ -1537,6 +1543,14 @@ static int wled_configure(struct wled *wled)
> return -EINVAL;
> }
>
> + for (i = 0; i < string_len; ++i) {
> + if (wled->cfg.enabled_strings[i] >= wled->max_string_count) {
> + dev_err(dev, "qcom,enabled-strings index %d at %d is out of bounds\n",
> + wled->cfg.enabled_strings[i], i);
> + return -EINVAL;
> + }
> + }
> +
> cfg->num_strings = string_len;
> }
>
> --
> 2.33.0
>
