commit fda4600e41ded0b8f0a54222e2dc8a85d53b4121
author Hal Canary <halcanary@google.com> Mon May 08 17:17:47 2017 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Tue May 09 17:36:27 2017 +0000
tree 59436090ce0bd63c36a5230aab4f78215dd43e33
parent 87345661516731e02c6087bfc8698316b36933fc

SkPerlinNoiseShader: handle pathological inputs

BUG=skia:6429
Change-Id: Ifc20c1f480c1396e40ab7fc3a3789aa7c2ae5d85
Reviewed-on: https://skia-review.googlesource.com/15896
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>

src/effects/SkPerlinNoiseShader.cpp

diff --git a/src/effects/SkPerlinNoiseShader.cpp b/src/effects/SkPerlinNoiseShader.cpp
index 72a26d5..1f19326 100644
--- a/src/effects/SkPerlinNoiseShader.cpp
+++ b/src/effects/SkPerlinNoiseShader.cpp
@@ -357,6 +357,9 @@
     int b11 = (j + noiseY.nextNoisePositionIntegerValue) & kBlockMask;
     SkScalar sx = smoothCurve(noiseX.noisePositionFractionValue);
     SkScalar sy = smoothCurve(noiseY.noisePositionFractionValue);
+    if (sx < 0 || sy < 0 || sx > 1 || sy > 1) {
+        return 0;  // Check for pathological inputs.
+    }
     // This is taken 1:1 from SVG spec: http://www.w3.org/TR/SVG11/filters.html#feTurbulenceElement
     SkPoint fractionValue = SkPoint::Make(noiseX.noisePositionFractionValue,
                                           noiseY.noisePositionFractionValue); // Offset (0,0)