Skip to content

ICU-23337 Fix undefined behavior in list_format_fuzzer: validate enum values #3890

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
OwenSanzas wants to merge 1 commit into
base: main
Choose a base branch
from
Open

ICU-23337 Fix undefined behavior in list_format_fuzzer: validate enum values #3890

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
34 changes: 16 additions & 18 deletions icu4c/source/test/fuzzer/list_format_fuzzer.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -22,19 +22,28 @@ void TestFormat(icu::ListFormatter* listFormat, const icu::UnicodeString* items)
}
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
uint16_t rnd;
UListFormatterType type;
UListFormatterWidth width;
if (size < sizeof(rnd) + sizeof(type) + sizeof(width)) return 0;
int32_t raw_type;
int32_t raw_width;
if (size < sizeof(rnd) + sizeof(raw_type) + sizeof(raw_width)) return 0;
icu::StringPiece fuzzData(reinterpret_cast<const char *>(data), size);

std::memcpy(&rnd, fuzzData.data(), sizeof(rnd));
icu::Locale locale = GetRandomLocale(rnd);
fuzzData.remove_prefix(sizeof(rnd));

std::memcpy(&type, fuzzData.data(), sizeof(type));
fuzzData.remove_prefix(sizeof(type));
std::memcpy(&width, fuzzData.data(), sizeof(width));
fuzzData.remove_prefix(sizeof(width));
std::memcpy(&raw_type, fuzzData.data(), sizeof(raw_type));
fuzzData.remove_prefix(sizeof(raw_type));
std::memcpy(&raw_width, fuzzData.data(), sizeof(raw_width));
fuzzData.remove_prefix(sizeof(raw_width));

// Ensure non-negative before modulo.
int32_t type_index = raw_type < 0 ? -raw_type : raw_type;
int32_t width_index = raw_width < 0 ? -raw_width : raw_width;

UListFormatterType type = static_cast<UListFormatterType>(
type_index % (static_cast<int>(ULISTFMT_TYPE_UNITS) + 1));
UListFormatterWidth width = static_cast<UListFormatterWidth>(
width_index % (static_cast<int>(ULISTFMT_WIDTH_NARROW) + 1));

size_t len = fuzzData.size() / sizeof(char16_t);
icu::UnicodeString text(false, reinterpret_cast<const char16_t*>(fuzzData.data()), len);
Expand All @@ -54,16 +63,5 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
TestFormat(listFormat.get(), items);
}

status = U_ZERO_ERROR;
type = static_cast<UListFormatterType>(
static_cast<int>(type) % (static_cast<int>(ULISTFMT_TYPE_UNITS) + 1));
width = static_cast<UListFormatterWidth>(
static_cast<int>(width) % (static_cast<int>(ULISTFMT_WIDTH_NARROW) + 1));
listFormat.reset(
icu::ListFormatter::createInstance(locale, type, width, status));
if (U_SUCCESS(status)) {
TestFormat(listFormat.get(), items);
}

return EXIT_SUCCESS;
}