Add 2 fuzz targets for image decoding (oss-fuzz)

This also adds in a few small guards to prevent libfuzzer from frequently
running out of memory when an image claims to have billions of pixels.

Bug: skia:
Change-Id: I47a9daac832c4d85a42000698482b61721c38880
Reviewed-on: https://skia-review.googlesource.com/106264
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/fuzz/oss_fuzz/FuzzImage.cpp b/fuzz/oss_fuzz/FuzzImage.cpp
new file mode 100644
index 0000000000..0f0f6f5a43
--- /dev/null
+++ b/fuzz/oss_fuzz/FuzzImage.cpp
@@ -0,0 +1,37 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkImage.h"
+#include "SkPaint.h"
+#include "SkCanvas.h"
+#include "SkData.h"
+#include "SkSurface.h"
+
+void FuzzImage(sk_sp<SkData> bytes) {
+    auto img = SkImage::MakeFromEncoded(bytes);
+    if (nullptr == img.get()) {
+        return;
+    }
+
+    auto s = SkSurface::MakeRasterN32Premul(128, 128);
+    if (!s) {
+        // May return nullptr in memory-constrained fuzzing environments
+        return;
+    }
+
+    SkPaint p;
+    s->getCanvas()->drawImage(img, 0, 0, &p);
+
+}
+
+#if defined(IS_FUZZING_WITH_LIBFUZZER)
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
+    auto bytes = SkData::MakeWithoutCopy(data, size);
+    FuzzImage(bytes);
+    return 0;
+}
+#endif