diff --git a/fuzzing/fuzz-targets/fuzz_submodule.py b/fuzzing/fuzz-targets/fuzz_submodule.py index ca47690ea..997133b70 100644 --- a/fuzzing/fuzz-targets/fuzz_submodule.py +++ b/fuzzing/fuzz-targets/fuzz_submodule.py @@ -3,25 +3,16 @@ import os import tempfile from configparser import ParsingError -from utils import is_expected_exception_message, get_max_filename_length - -if getattr(sys, "frozen", False) and hasattr(sys, "_MEIPASS"): # pragma: no cover - path_to_bundled_git_binary = os.path.abspath(os.path.join(os.path.dirname(__file__), "git")) - os.environ["GIT_PYTHON_GIT_EXECUTABLE"] = path_to_bundled_git_binary - +from utils import ( + setup_git_environment, + handle_exception, + get_max_filename_length, +) + +# Setup the git environment +setup_git_environment() from git import Repo, GitCommandError, InvalidGitRepositoryError -if not sys.warnoptions: # pragma: no cover - # The warnings filter below can be overridden by passing the -W option - # to the Python interpreter command line or setting the `PYTHONWARNINGS` environment variable. - import warnings - import logging - - # Fuzzing data causes some modules to generate a large number of warnings - # which are not usually interesting and make the test output hard to read, so we ignore them. - warnings.simplefilter("ignore") - logging.getLogger().setLevel(logging.ERROR) - def TestOneInput(data): fdp = atheris.FuzzedDataProvider(data) @@ -35,12 +26,13 @@ def TestOneInput(data): sub_repo = Repo.init(submodule_temp_dir, bare=fdp.ConsumeBool()) sub_repo.index.commit(fdp.ConsumeUnicodeNoSurrogates(fdp.ConsumeIntInRange(1, 512))) - submodule_name = f"submodule_{fdp.ConsumeUnicodeNoSurrogates(fdp.ConsumeIntInRange(1, 512))}" + submodule_name = fdp.ConsumeUnicodeNoSurrogates( + fdp.ConsumeIntInRange(1, max(1, get_max_filename_length(repo.working_tree_dir))) + ) submodule_path = os.path.join(repo.working_tree_dir, submodule_name) - submodule_url = sub_repo.git_dir - submodule = repo.create_submodule(submodule_name, submodule_path, url=submodule_url) - repo.index.commit(f"Added submodule {submodule_name}") + submodule = repo.create_submodule(submodule_name, submodule_path, url=sub_repo.git_dir) + repo.index.commit("Added submodule") with submodule.config_writer() as writer: key_length = fdp.ConsumeIntInRange(1, max(1, fdp.remaining_bytes())) @@ -88,18 +80,11 @@ def TestOneInput(data): BrokenPipeError, ): return -1 - except ValueError as e: - expected_messages = [ - "SHA is empty", - "Reference at", - "embedded null byte", - "This submodule instance does not exist anymore", - "cmd stdin was empty", - ] - if is_expected_exception_message(e, expected_messages): + except Exception as e: + if isinstance(e, ValueError) and "embedded null byte" in str(e): return -1 else: - raise e + return handle_exception(e) def main(): diff --git a/fuzzing/fuzz-targets/utils.py b/fuzzing/fuzz-targets/utils.py index f522d2959..97e6eab98 100644 --- a/fuzzing/fuzz-targets/utils.py +++ b/fuzzing/fuzz-targets/utils.py @@ -1,6 +1,9 @@ import atheris # pragma: no cover import os # pragma: no cover -from typing import List # pragma: no cover +import re # pragma: no cover +import traceback # pragma: no cover +import sys # pragma: no cover +from typing import Set, Tuple, List # pragma: no cover @atheris.instrument_func @@ -35,3 +38,85 @@ def get_max_filename_length(path: str) -> int: # pragma: no cover int: The maximum filename length. """ return os.pathconf(path, "PC_NAME_MAX") + + +@atheris.instrument_func +def read_lines_from_file(file_path: str) -> list: + """Read lines from a file and return them as a list.""" + try: + with open(file_path, "r") as f: + return [line.strip() for line in f if line.strip()] + except FileNotFoundError: + print(f"File not found: {file_path}") + return [] + except IOError as e: + print(f"Error reading file {file_path}: {e}") + return [] + + +@atheris.instrument_func +def load_exception_list(file_path: str = "explicit-exceptions-list.txt") -> Set[Tuple[str, str]]: + """Load and parse the exception list from a default or specified file.""" + try: + bundle_dir = os.path.dirname(os.path.abspath(__file__)) + full_path = os.path.join(bundle_dir, file_path) + lines = read_lines_from_file(full_path) + exception_list: Set[Tuple[str, str]] = set() + for line in lines: + match = re.match(r"(.+):(\d+):", line) + if match: + file_path: str = match.group(1).strip() + line_number: str = str(match.group(2).strip()) + exception_list.add((file_path, line_number)) + return exception_list + except Exception as e: + print(f"Error loading exception list: {e}") + return set() + + +@atheris.instrument_func +def match_exception_with_traceback(exception_list: Set[Tuple[str, str]], exc_traceback) -> bool: + """Match exception traceback with the entries in the exception list.""" + for filename, lineno, _, _ in traceback.extract_tb(exc_traceback): + for file_pattern, line_pattern in exception_list: + # Ensure filename and line_number are strings for regex matching + if re.fullmatch(file_pattern, filename) and re.fullmatch(line_pattern, str(lineno)): + return True + return False + + +@atheris.instrument_func +def check_exception_against_list(exc_traceback, exception_file: str = "explicit-exceptions-list.txt") -> bool: + """Check if the exception traceback matches any entry in the exception list.""" + exception_list = load_exception_list(exception_file) + return match_exception_with_traceback(exception_list, exc_traceback) + + +@atheris.instrument_func +def handle_exception(e: Exception) -> int: + """Encapsulate exception handling logic for reusability.""" + exc_traceback = e.__traceback__ + if check_exception_against_list(exc_traceback): + return -1 + else: + raise e + + +@atheris.instrument_func +def setup_git_environment() -> None: + """Set up the environment variables for Git.""" + bundle_dir = os.path.dirname(os.path.abspath(__file__)) + if getattr(sys, "frozen", False) and hasattr(sys, "_MEIPASS"): # pragma: no cover + bundled_git_binary_path = os.path.join(bundle_dir, "git") + os.environ["GIT_PYTHON_GIT_EXECUTABLE"] = bundled_git_binary_path + + if not sys.warnoptions: # pragma: no cover + # The warnings filter below can be overridden by passing the -W option + # to the Python interpreter command line or setting the `PYTHONWARNINGS` environment variable. + import warnings + import logging + + # Fuzzing data causes some modules to generate a large number of warnings + # which are not usually interesting and make the test output hard to read, so we ignore them. + warnings.simplefilter("ignore") + logging.getLogger().setLevel(logging.ERROR) diff --git a/fuzzing/oss-fuzz-scripts/build.sh b/fuzzing/oss-fuzz-scripts/build.sh index e0b3a50ab..c156e872d 100644 --- a/fuzzing/oss-fuzz-scripts/build.sh +++ b/fuzzing/oss-fuzz-scripts/build.sh @@ -15,5 +15,5 @@ find "$SRC" -maxdepth 1 \ # Build fuzzers in $OUT. find "$SRC/gitpython/fuzzing" -name 'fuzz_*.py' -print0 | while IFS= read -r -d '' fuzz_harness; do - compile_python_fuzzer "$fuzz_harness" --add-binary="$(command -v git):." + compile_python_fuzzer "$fuzz_harness" --add-binary="$(command -v git):." --add-data="$SRC/explicit-exceptions-list.txt:." done diff --git a/fuzzing/oss-fuzz-scripts/container-environment-bootstrap.sh b/fuzzing/oss-fuzz-scripts/container-environment-bootstrap.sh index bbdcf5357..924a3cbf3 100755 --- a/fuzzing/oss-fuzz-scripts/container-environment-bootstrap.sh +++ b/fuzzing/oss-fuzz-scripts/container-environment-bootstrap.sh @@ -91,6 +91,17 @@ create_seed_corpora_zips "$WORK/qa-assets/gitpython/corpora" prepare_dictionaries_for_fuzz_targets "$WORK/qa-assets/gitpython/dictionaries" "$SRC/gitpython/fuzzing" +pushd "$SRC/gitpython/" +# Search for 'raise' and 'assert' statements in Python files within GitPython's source code and submodules, saving the +# matched file path, line number, and line content to a file named 'explicit-exceptions-list.txt'. +# This file can then be used by fuzz harnesses to check exception tracebacks and filter out explicitly raised or otherwise +# anticipated exceptions to reduce false positive test failures. + +git grep -n --recurse-submodules -e '\braise\b' -e '\bassert\b' -- '*.py' -- ':!setup.py' -- ':!test/**' -- ':!fuzzing/**' > "$SRC/explicit-exceptions-list.txt" + +popd + + # The OSS-Fuzz base image has outdated dependencies by default so we upgrade them below. python3 -m pip install --upgrade pip # Upgrade to the latest versions known to work at the time the below changes were introduced: diff --git a/pyproject.toml b/pyproject.toml index 603e2597c..6cf4b3f5d 100644 --- a/pyproject.toml +++ b/pyproject.toml @@ -78,6 +78,10 @@ lint.unfixable = [ "test/**" = [ "B018", # useless-expression ] +"fuzzing/fuzz-targets/**" = [ + "E402", # environment setup must happen before the `git` module is imported, thus cannot happen at top of file +] + [tool.codespell] ignore-words-list="gud,doesnt"