Limit morphology radius to 100 pixels

This limit is arbitrary, but hopefully prevents pathological (or
malicious) SVG content from consuming huge amounts of CPU/GPU time,
without impacting any legitimate uses of feMorphology. (Typical usage
has a much smaller radius).

Bug: chromium:1123035
Change-Id: I4405bc595128e9a6287eb5efa1be14621baa3a00
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/315219
Reviewed-by: Mike Reed <[email protected]>
Commit-Queue: Brian Osman <[email protected]>

Author: brianosman

src/effects/imagefilters/SkMorphologyImageFilter.cpp

@@ -637,7 +637,9 @@ sk_sp<SkSpecialImage> SkMorphologyImageFilterImpl::onFilterImage(const Context&
     int height = SkScalarRoundToInt(radius.height());
 
     // Width (or height) must fit in a signed 32-bit int to avoid UBSAN issues (crbug.com/1018190)
-    constexpr int kMaxRadius = (std::numeric_limits<int>::max() - 1) / 2;
+    // Further, we limit the radius to something much smaller, to avoid extremely slow draw calls:
+    // (crbug.com/1123035):
+    constexpr int kMaxRadius = 100; // (std::numeric_limits<int>::max() - 1) / 2;
 
     if (width < 0 || height < 0 || width > kMaxRadius || height > kMaxRadius) {
         return nullptr;