fix alpha-filtering crash when image width is larger than radius
(we also limit radius based on height too, for good measure, although it's not an asan bug)
fixes oss-fuzz issue
@@ -261,9 +261,15 @@ static void CleanupParams(SmoothParams* const p) {
int WebPDequantizeLevels(uint8_t* const data, int width, int height, int stride,
int strength) {
- const int radius = 4 * strength / 100;
+ int radius = 4 * strength / 100;
+
if (strength < 0 || strength > 100) return 0;
if (data == NULL || width <= 0 || height <= 0) return 0; // bad params
+
+ // limit the filter size to not exceed the image dimensions
+ if (2 * radius + 1 > width) radius = (width - 1) >> 1;
+ if (2 * radius + 1 > height) radius = (height - 1) >> 1;
+
if (radius > 0) {
SmoothParams p;
memset(&p, 0, sizeof(p));
