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")
Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx>
Reviewed-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
---
drivers/video/backlight/qcom-wled.c | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
index d094299c2a48..8a42ed89c59c 100644
--- a/drivers/video/backlight/qcom-wled.c
+++ b/drivers/video/backlight/qcom-wled.c
@@ -1528,12 +1528,28 @@ static int wled_configure(struct wled *wled)
string_len = of_property_count_elems_of_size(dev->of_node,
"qcom,enabled-strings",
sizeof(u32));
- if (string_len > 0)
+ 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;
+ }
+
of_property_read_u32_array(dev->of_node,
"qcom,enabled-strings",
wled->cfg.enabled_strings,
sizeof(u32));
+ 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;
+ }
+ }
+ }
+
return 0;
}
--
2.33.1
