v8/test/fuzzer/regexp-builtins.cc
Jakob Gruber 82fdb91505 [regexp-builtins-fuzzer] Print generated source in verbose mode
My standard procedure for debugging regexp builtin fuzzer finds is to
turn on verbose mode and run the repro. This extends verbose output to
include the generated script which contains e.g. the regexp pattern,
the subject string, and the actual function call.

Tbr: yangguo@chromium.org
Bug: v8:8968
Change-Id: I0c7e930f4cbd34014f2781ca280919c5b002b049
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1511276
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60120}
2019-03-08 11:40:41 +00:00

456 lines
16 KiB
C++

// Copyright 2017 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 <functional>
#include <string>
#include "include/v8.h"
#include "src/heap/factory.h"
#include "src/objects-inl.h"
#include "src/regexp/jsregexp.h"
#include "test/fuzzer/fuzzer-support.h"
// This is a hexdump of test/fuzzer/regexp_builtins/mjsunit.js generated using
// `xxd -i mjsunit.js`. It contains the `assertEquals` JS function used below.
#include "test/fuzzer/regexp_builtins/mjsunit.js.h"
namespace v8 {
namespace internal {
namespace {
constexpr bool kVerbose = false; // For debugging, verbose error messages.
constexpr uint32_t kRegExpBuiltinsFuzzerHashSeed = 83;
#define REGEXP_BUILTINS(V) \
V(Exec, exec) \
V(Match, Symbol.match) \
V(Replace, Symbol.replace) \
V(Search, Symbol.search) \
V(Split, Symbol.split) \
V(Test, test)
struct FuzzerArgs {
FuzzerArgs(const uint8_t* input_data, size_t input_length,
v8::Local<v8::Context> context, Isolate* isolate)
: input_cursor(0),
input_data(input_data),
input_length(input_length),
context(context),
isolate(isolate) {}
size_t input_cursor;
const uint8_t* const input_data;
const size_t input_length;
v8::Local<v8::Context> context;
Isolate* const isolate;
};
enum RegExpBuiltin {
#define CASE(name, ...) kRegExpPrototype##name,
REGEXP_BUILTINS(CASE)
#undef CASE
kRegExpBuiltinCount,
};
#define CASE(name, ...) void TestRegExpPrototype##name(FuzzerArgs* args);
REGEXP_BUILTINS(CASE)
#undef CASE
v8::Local<v8::String> v8_str(const char* s) {
return v8::String::NewFromUtf8(v8::Isolate::GetCurrent(), s,
v8::NewStringType::kNormal)
.ToLocalChecked();
}
v8::MaybeLocal<v8::Value> CompileRun(v8::Local<v8::Context> context,
const char* source) {
v8::Local<v8::Script> script;
v8::MaybeLocal<v8::Script> maybe_script =
v8::Script::Compile(context, v8_str(source));
if (!maybe_script.ToLocal(&script)) return v8::MaybeLocal<v8::Value>();
return script->Run(context);
}
uint8_t RandomByte(FuzzerArgs* args) {
// Silently wraps to the beginning of input data. Ideally, input data should
// be long enough to avoid that.
const size_t index = args->input_cursor;
CHECK(index < args->input_length);
args->input_cursor = (index + 1) % args->input_length;
return args->input_data[index];
}
void CompileMjsunit(const FuzzerArgs* args) {
std::string source(
reinterpret_cast<const char*>(test_fuzzer_regexp_builtins_mjsunit_js),
test_fuzzer_regexp_builtins_mjsunit_js_len);
CompileRun(args->context, source.c_str()).ToLocalChecked();
}
std::string NaiveEscape(const std::string& input, char escaped_char) {
std::string out;
for (size_t i = 0; i < input.size(); i++) {
// Just omit newlines and \0 chars and naively replace other escaped chars.
const char c = input[i];
if (c == '\r' || c == '\n' || c == '\0') continue;
out += (input[i] == escaped_char) ? '_' : c;
}
// Disallow trailing backslashes as they mess with our naive source string
// concatenation.
if (!out.empty() && out.back() == '\\') out.back() = '_';
return out;
}
std::string GenerateRandomString(FuzzerArgs* args, size_t length) {
// Limited to an ASCII subset for now.
std::string s(length, '\0');
for (size_t i = 0; i < length; i++) {
s[i] = static_cast<char>((RandomByte(args) % 0x5F) + 0x20);
}
return s;
}
std::string GenerateRandomPattern(FuzzerArgs* args) {
const int kMaxPatternLength = 16;
std::string s =
GenerateRandomString(args, (RandomByte(args) % kMaxPatternLength) + 1);
// A leading '*' would be a comment instead of a regexp literal.
if (s[0] == '*') s[0] = '.';
return s;
}
std::string PickRandomPresetPattern(FuzzerArgs* args) {
static const char* preset_patterns[] = {
".", // Always matches.
"\\P{Any}", // Never matches.
"^", // Zero-width assertion, matches once.
"(?=.)", // Zero-width assertion, matches at every position.
"\\b", // Zero-width assertion, matches at each word boundary.
"()", // Zero-width assertion, matches at every position with groups.
"(?<a>)", // Likewise but with named groups.
"((((.).).).)", "(?<a>(?<b>(?<c>(?<d>.).).).)",
// Copied from
// https://cs.chromium.org/chromium/src/testing/libfuzzer/fuzzers/dicts/regexp.dict
"?", "abc", "()", "[]", "abc|def", "abc|def|ghi", "^xxx$",
"ab\\b\\d\\bcd", "\\w|\\d", "a*?", "abc+", "abc+?", "xyz?", "xyz??",
"xyz{0,1}", "xyz{0,1}?", "xyz{93}", "xyz{1,32}", "xyz{1,32}?", "xyz{1,}",
"xyz{1,}?", "a\\fb\\nc\\rd\\te\\vf", "a\\nb\\bc", "(?:foo)", "(?: foo )",
"foo|(bar|baz)|quux", "foo(?=bar)baz", "foo(?!bar)baz", "foo(?<=bar)baz",
"foo(?<!bar)baz", "()", "(?=)", "[]", "[x]", "[xyz]", "[a-zA-Z0-9]",
"[-123]", "[^123]", "]", "}", "[a-b-c]", "[x\\dz]", "[\\d-z]",
"[\\d-\\d]", "[z-\\d]", "\\cj\\cJ\\ci\\cI\\ck\\cK", "\\c!", "\\c_",
"\\c~", "[\\c!]", "[\\c_]", "[\\c~]", "[\\ca]", "[\\cz]", "[\\cA]",
"[\\cZ]", "[\\c1]", "\\[\\]\\{\\}\\(\\)\\%\\^\\#\\ ",
"[\\[\\]\\{\\}\\(\\)\\%\\^\\#\\ ]", "\\8", "\\9", "\\11", "\\11a",
"\\011", "\\118", "\\111", "\\1111", "(x)(x)(x)\\1", "(x)(x)(x)\\2",
"(x)(x)(x)\\3", "(x)(x)(x)\\4", "(x)(x)(x)\\1*", "(x)(x)(x)\\3*",
"(x)(x)(x)\\4*", "(x)(x)(x)(x)(x)(x)(x)(x)(x)(x)\\10",
"(x)(x)(x)(x)(x)(x)(x)(x)(x)(x)\\11", "(a)\\1", "(a\\1)", "(\\1a)",
"(\\2)(\\1)", "(?=a){0,10}a", "(?=a){1,10}a", "(?=a){9,10}a", "(?!a)?a",
"\\1(a)", "(?!(a))\\1", "(?!\\1(a\\1)\\1)\\1",
"\\1\\2(a(?:\\1(b\\1\\2))\\2)\\1", "[\\0]", "[\\11]", "[\\11a]",
"[\\011]", "[\\00011]", "[\\118]", "[\\111]", "[\\1111]", "\\x60",
"\\x3z", "\\c", "\\u0034", "\\u003z", "foo[z]*", "\\u{12345}",
"\\u{12345}\\u{23456}", "\\u{12345}{3}", "\\u{12345}*", "\\ud808\\udf45*",
"[\\ud808\\udf45-\\ud809\\udccc]", "a", "a|b", "a\\n", "a$", "a\\b!",
"a\\Bb", "a*?", "a?", "a??", "a{0,1}?", "a{1,2}?", "a+?", "(a)", "(a)\\1",
"(\\1a)", "\\1(a)", "a\\s", "a\\S", "a\\D", "a\\w", "a\\W", "a.", "a\\q",
"a[a]", "a[^a]", "a[a-z]", "a(?:b)", "a(?=b)", "a(?!b)", "\\x60",
"\\u0060", "\\cA", "\\q", "\\1112", "(a)\\1", "(?!a)?a\\1",
"(?:(?=a))a\\1", "a{}", "a{,}", "a{", "a{z}", "a{12z}", "a{12,",
"a{12,3b", "{}", "{,}", "{", "{z}", "{1z}", "{12,", "{12,3b", "a", "abc",
"a[bc]d", "a|bc", "ab|c", "a||bc", "(?:ab)", "(?:ab|cde)", "(?:ab)|cde",
"(ab)", "(ab|cde)", "(ab)\\1", "(ab|cde)\\1", "(?:ab)?", "(?:ab)+", "a?",
"a+", "a??", "a*?", "a+?", "(?:a?)?", "(?:a+)?", "(?:a?)+", "(?:a*)+",
"(?:a+)+", "(?:a?)*", "(?:a*)*", "(?:a+)*", "a{0}", "(?:a+){0,0}", "a*b",
"a+b", "a*b|c", "a+b|c", "(?:a{5,1000000}){3,1000000}", "(?:ab){4,7}",
"a\\bc", "a\\sc", "a\\Sc", "a(?=b)c", "a(?=bbb|bb)c", "a(?!bbb|bb)c",
"\xe2\x81\xa3", "[\xe2\x81\xa3]", "\xed\xb0\x80", "\xed\xa0\x80",
"(\xed\xb0\x80)\x01", "((\xed\xa0\x80))\x02", "\xf0\x9f\x92\xa9", "\x01",
"\x0f", "[-\xf0\x9f\x92\xa9]+", "[\xf0\x9f\x92\xa9-\xf4\x8f\xbf\xbf]",
"(?<=)", "(?<=a)", "(?<!)", "(?<!a)", "(?<a>)", "(?<a>.)",
"(?<a>.)\\k<a>", "\\p{Script=Greek}", "\\P{sc=Greek}",
"\\p{Script_Extensions=Greek}", "\\P{scx=Greek}",
"\\p{General_Category=Decimal_Number}", "\\P{gc=Decimal_Number}",
"\\p{gc=Nd}", "\\P{Decimal_Number}", "\\p{Nd}", "\\P{Any}",
"\\p{Changes_When_NFKC_Casefolded}",
};
static constexpr int preset_pattern_count = arraysize(preset_patterns);
STATIC_ASSERT(preset_pattern_count < 0xFF);
return std::string(preset_patterns[RandomByte(args) % preset_pattern_count]);
}
std::string PickPattern(FuzzerArgs* args) {
if ((RandomByte(args) & 3) == 0) {
return NaiveEscape(GenerateRandomPattern(args), '/');
} else {
return PickRandomPresetPattern(args);
}
}
std::string GenerateRandomString(FuzzerArgs* args) {
const int kMaxStringLength = 64;
return GenerateRandomString(args, RandomByte(args) % kMaxStringLength);
}
std::string PickSubjectString(FuzzerArgs* args) {
if ((RandomByte(args) & 0xF) == 0) {
// Sometimes we have a two-byte subject string.
return "f\\uD83D\\uDCA9ba\\u2603";
} else {
return NaiveEscape(GenerateRandomString(args), '\'');
}
}
std::string PickReplacementForReplace(FuzzerArgs* args) {
static const char* candidates[] = {
"'X'",
"'$1$2$3'",
"'$$$&$`$\\'$1'",
"() => 'X'",
"(arg0, arg1, arg2, arg3, arg4) => arg0 + arg1 + arg2 + arg3 + arg4",
"() => 42",
};
static const int candidate_count = arraysize(candidates);
if ((RandomByte(args) & 1) == 0) {
return candidates[RandomByte(args) % candidate_count];
} else {
return std::string("'") + NaiveEscape(GenerateRandomString(args), '\'') +
std::string("'");
}
}
std::string PickLimitForSplit(FuzzerArgs* args) {
// clang-format off
switch (RandomByte(args) & 0x3) {
case 0: return "undefined";
case 1: return "'not a number'";
case 2: return std::to_string(Smi::kMaxValue + RandomByte(args));
case 3: return std::to_string(RandomByte(args));
default: UNREACHABLE();
} // clang-format on
}
std::string GenerateRandomFlags(FuzzerArgs* args) {
constexpr size_t kFlagCount = JSRegExp::FlagCount();
CHECK_EQ(JSRegExp::kDotAll, 1 << (kFlagCount - 1));
STATIC_ASSERT((1 << kFlagCount) - 1 < 0xFF);
const size_t flags = RandomByte(args) & ((1 << kFlagCount) - 1);
int cursor = 0;
char buffer[kFlagCount] = {'\0'};
if (flags & JSRegExp::kGlobal) buffer[cursor++] = 'g';
if (flags & JSRegExp::kIgnoreCase) buffer[cursor++] = 'i';
if (flags & JSRegExp::kMultiline) buffer[cursor++] = 'm';
if (flags & JSRegExp::kSticky) buffer[cursor++] = 'y';
if (flags & JSRegExp::kUnicode) buffer[cursor++] = 'u';
if (flags & JSRegExp::kDotAll) buffer[cursor++] = 's';
return std::string(buffer, cursor);
}
std::string GenerateRandomLastIndex(FuzzerArgs* args) {
static const char* candidates[] = {
"undefined", "-1", "0",
"1", "2", "3",
"4", "5", "6",
"7", "8", "9",
"50", "4294967296", "2147483647",
"2147483648", "NaN", "Not a Number",
};
static const int candidate_count = arraysize(candidates);
return candidates[RandomByte(args) % candidate_count];
}
void RunTest(FuzzerArgs* args) {
switch (RandomByte(args) % kRegExpBuiltinCount) {
#define CASE(name, ...) \
case kRegExpPrototype##name: \
TestRegExpPrototype##name(args); \
break;
REGEXP_BUILTINS(CASE)
#undef CASE
default:
UNREACHABLE();
}
}
std::string GenerateSourceString(FuzzerArgs* args, const std::string& test) {
std::string pattern = PickPattern(args);
std::string flags = GenerateRandomFlags(args);
std::string last_index = GenerateRandomLastIndex(args);
std::string subject = PickSubjectString(args);
// clang-format off
std::stringstream ss;
ss << "function test() {\n"
<< " const re = /" << pattern<< "/"
<< flags << ";\n"
<< " re.lastIndex = " << last_index << ";\n"
<< " const str = '" << subject << "';\n"
<< " let result = null;\n"
<< " let exception = null;\n"
<< " try {\n"
<< " result = " << test << "\n"
<< " } catch (e) {\n"
<< " exception = e;\n"
<< " }\n"
<< " return { result: result, re: re, exception: exception };\n"
<< "}\n"
<< "%SetForceSlowPath(false);\n"
<< "test(); // Run once ahead of time to compile the regexp.\n"
<< "const fast = test();\n"
<< "%SetForceSlowPath(true);\n"
<< "const slow = test();\n"
<< "%SetForceSlowPath(false);\n";
// clang-format on
std::string source = ss.str();
if (kVerbose) {
fprintf(stderr, "Generated source:\n```\n%s\n```\n", source.c_str());
}
return source;
}
void PrintExceptionMessage(v8::Isolate* isolate, v8::TryCatch* try_catch) {
CHECK(try_catch->HasCaught());
static const int kBufferLength = 256;
char buffer[kBufferLength + 1];
try_catch->Message()->Get()->WriteOneByte(
isolate, reinterpret_cast<uint8_t*>(&buffer[0]), 0, kBufferLength);
fprintf(stderr, "%s\n", buffer);
}
bool ResultsAreIdentical(FuzzerArgs* args) {
std::string source =
"assertEquals(fast.exception, slow.exception);\n"
"assertEquals(fast.result, slow.result);\n"
"if (fast.result !== null)\n"
" assertEquals(fast.result.groups, slow.result.groups);\n"
"assertEquals(fast.re.lastIndex, slow.re.lastIndex);\n";
v8::Local<v8::Value> result;
v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(args->isolate);
v8::TryCatch try_catch(isolate);
if (!CompileRun(args->context, source.c_str()).ToLocal(&result)) {
PrintExceptionMessage(isolate, &try_catch);
args->isolate->clear_pending_exception();
return false;
}
return true;
}
void CompileRunAndVerify(FuzzerArgs* args, const std::string& source) {
v8::Local<v8::Value> result;
v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(args->isolate);
v8::TryCatch try_catch(isolate);
if (!CompileRun(args->context, source.c_str()).ToLocal(&result)) {
args->isolate->clear_pending_exception();
// No need to verify result if an exception was thrown here, since that
// implies a syntax error somewhere in the pattern or string. We simply
// ignore those.
if (kVerbose) {
PrintExceptionMessage(isolate, &try_catch);
fprintf(stderr, "Failed to run script:\n```\n%s\n```\n", source.c_str());
}
return;
}
if (!ResultsAreIdentical(args)) {
uint32_t hash = StringHasher::HashSequentialString(
args->input_data, static_cast<int>(args->input_length),
kRegExpBuiltinsFuzzerHashSeed);
V8_Fatal(__FILE__, __LINE__,
"!ResultAreIdentical(args); RegExpBuiltinsFuzzerHash=%x", hash);
}
}
void TestRegExpPrototypeExec(FuzzerArgs* args) {
std::string test = "re.exec(str);";
std::string source = GenerateSourceString(args, test);
CompileRunAndVerify(args, source);
}
void TestRegExpPrototypeMatch(FuzzerArgs* args) {
std::string test = "re[Symbol.match](str);";
std::string source = GenerateSourceString(args, test);
CompileRunAndVerify(args, source);
}
void TestRegExpPrototypeReplace(FuzzerArgs* args) {
std::string replacement = PickReplacementForReplace(args);
std::string test = "re[Symbol.replace](str, " + replacement + ");";
std::string source = GenerateSourceString(args, test);
CompileRunAndVerify(args, source);
}
void TestRegExpPrototypeSearch(FuzzerArgs* args) {
std::string test = "re[Symbol.search](str);";
std::string source = GenerateSourceString(args, test);
CompileRunAndVerify(args, source);
}
void TestRegExpPrototypeSplit(FuzzerArgs* args) {
std::string limit = PickLimitForSplit(args);
std::string test = "re[Symbol.split](str, " + limit + ");";
std::string source = GenerateSourceString(args, test);
CompileRunAndVerify(args, source);
}
void TestRegExpPrototypeTest(FuzzerArgs* args) {
std::string test = "re.test(str);";
std::string source = GenerateSourceString(args, test);
CompileRunAndVerify(args, source);
}
#undef REGEXP_BUILTINS
} // namespace
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
if (size < 64) return 0; // Need a minimal amount of randomness to do stuff.
// Flag definitions.
FLAG_allow_natives_syntax = true;
// V8 setup.
v8_fuzzer::FuzzerSupport* support = v8_fuzzer::FuzzerSupport::Get();
v8::Isolate* isolate = support->GetIsolate();
Isolate* i_isolate = reinterpret_cast<i::Isolate*>(isolate);
v8::Isolate::Scope isolate_scope(isolate);
v8::HandleScope handle_scope(isolate);
v8::Local<v8::Context> context = support->GetContext();
v8::Context::Scope context_scope(context);
v8::TryCatch try_catch(isolate);
CHECK(!i_isolate->has_pending_exception());
// And run.
FuzzerArgs args(data, size, context, i_isolate);
CompileMjsunit(&args);
RunTest(&args);
CHECK(!i_isolate->has_pending_exception());
return 0;
}
} // namespace internal
} // namespace v8