v8/test/fuzzer/parser.cc
mmoroz 9662833931 [fuzzer] Add input validation in the beginning of the parser fuzz target.
Non-printable characters do not make sense.
Inputs with non balanced brackets are mostly useless as well.

This validation function makes the fuzzer 15-20x faster.

Also use -only_ascii=1 option of libFuzzer:
https://codereview.chromium.org/2875933003

BUG=chromium:584819

Review-Url: https://codereview.chromium.org/2881583002
Cr-Commit-Position: refs/heads/master@{#45367}
2017-05-17 10:36:10 +00:00

90 lines
2.5 KiB
C++

// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <limits.h>
#include <stddef.h>
#include <stdint.h>
#include "include/v8.h"
#include "src/objects-inl.h"
#include "src/objects.h"
#include "src/parsing/parse-info.h"
#include "src/parsing/parsing.h"
#include "src/parsing/preparser.h"
#include "test/fuzzer/fuzzer-support.h"
#include <cctype>
#include <list>
bool IsValidInput(const uint8_t* data, size_t size) {
std::list<char> parentheses;
const char* ptr = reinterpret_cast<const char*>(data);
for (size_t i = 0; i != size; ++i) {
// Check that all characters in the data are valid.
if (!(std::isspace(ptr[i]) || std::isprint(ptr[i]))) {
return false;
}
// Check balance of parentheses in the data.
switch (ptr[i]) {
case '(':
case '[':
case '{':
parentheses.push_back(ptr[i]);
break;
case ')':
if (parentheses.back() != '(') return false;
parentheses.pop_back();
break;
case ']':
if (parentheses.back() != '[') return false;
parentheses.pop_back();
break;
case '}':
if (parentheses.back() != '{') return false;
parentheses.pop_back();
break;
default:
break;
}
}
return parentheses.empty();
}
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
if (!IsValidInput(data, size)) {
return 0;
}
v8_fuzzer::FuzzerSupport* support = v8_fuzzer::FuzzerSupport::Get();
v8::Isolate* isolate = support->GetIsolate();
v8::Isolate::Scope isolate_scope(isolate);
v8::HandleScope handle_scope(isolate);
v8::Context::Scope context_scope(support->GetContext());
v8::TryCatch try_catch(isolate);
v8::internal::Isolate* i_isolate =
reinterpret_cast<v8::internal::Isolate*>(isolate);
v8::internal::Factory* factory = i_isolate->factory();
if (size > INT_MAX) return 0;
v8::internal::MaybeHandle<v8::internal::String> source =
factory->NewStringFromOneByte(
v8::internal::Vector<const uint8_t>(data, static_cast<int>(size)));
if (source.is_null()) return 0;
v8::internal::Handle<v8::internal::Script> script =
factory->NewScript(source.ToHandleChecked());
v8::internal::ParseInfo info(script);
if (!v8::internal::parsing::ParseProgram(&info, i_isolate)) {
i_isolate->OptionalRescheduleException(true);
}
isolate->RequestGarbageCollectionForTesting(
v8::Isolate::kFullGarbageCollection);
return 0;
}