Merge pull request #78 from bshastry:libfuzzer-harness

PiperOrigin-RevId: 264241380

zippy_uncompress_fuzzer.cc

@@ -0,0 +1,57 @@
+// Copyright 2019 Google Inc. All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// libFuzzer harness for fuzzing snappy's decompression code.
+
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
+#include <string>
+
+#include "snappy.h"
+
+// Entry point for LibFuzzer.
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  std::string input(reinterpret_cast<const char*>(data), size);
+
+  // Avoid self-crafted decompression bombs.
+  size_t uncompressed_size;
+  constexpr size_t kMaxUncompressedSize = 1 << 20;
+  bool get_uncompressed_length_succeeded = snappy::GetUncompressedLength(
+      input.data(), input.size(), &uncompressed_size);
+  if (!get_uncompressed_length_succeeded ||
+      (uncompressed_size > kMaxUncompressedSize)) {
+    return 0;
+  }
+
+  std::string uncompressed;
+  // The return value of snappy::Uncompress() is ignored because decompression
+  // will fail on invalid inputs.
+  snappy::Uncompress(input.data(), input.size(), &uncompressed);
+  return 0;
+}