Merge pull request #1922 from DaveLak/fix-fuzz-submodule-expected-exceptions-handling

Add graceful handling of expected exceptions in fuzz_submodule.py

Author: Byron

fuzzing/fuzz-targets/fuzz_submodule.py

@@ -3,14 +3,23 @@
 importos
 importtempfile
 fromconfigparserimportParsingError
-fromutilsimportis_expected_exception_message
+fromutilsimportis_expected_exception_message, get_max_filename_length
+fromgitimportRepo, GitCommandError, InvalidGitRepositoryError
 
-ifgetattr(sys, "frozen", False) andhasattr(sys, "_MEIPASS"):
+ifgetattr(sys, "frozen", False) andhasattr(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
 
-withatheris.instrument_imports():
-fromgitimportRepo, GitCommandError, InvalidGitRepositoryError
+ifnotsys.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.
+importwarnings
+importlogging
+
+# 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)
 
 
 defTestOneInput(data):
@@ -42,12 +51,12 @@ def TestOneInput(data):
 writer.release()
 
 submodule.update(init=fdp.ConsumeBool(), dry_run=fdp.ConsumeBool(), force=fdp.ConsumeBool())
-
 submodule_repo=submodule.module()
-new_file_path=os.path.join(
-submodule_repo.working_tree_dir,
-f"new_file_{fdp.ConsumeUnicodeNoSurrogates(fdp.ConsumeIntInRange(1, 512))}",
+
+new_file_name=fdp.ConsumeUnicodeNoSurrogates(
+fdp.ConsumeIntInRange(1, max(1, get_max_filename_length(submodule_repo.working_tree_dir)))
  )
+new_file_path=os.path.join(submodule_repo.working_tree_dir, new_file_name)
 withopen(new_file_path, "wb") asnew_file:
 new_file.write(fdp.ConsumeBytes(fdp.ConsumeIntInRange(1, 512)))
 submodule_repo.index.add([new_file_path])
@@ -67,16 +76,24 @@ def TestOneInput(data):
  )
 repo.index.commit(f"Removed submodule {submodule_name}")
 
-except (ParsingError, GitCommandError, InvalidGitRepositoryError, FileNotFoundError, BrokenPipeError):
+except (
+ParsingError,
+GitCommandError,
+InvalidGitRepositoryError,
+FileNotFoundError,
+FileExistsError,
+IsADirectoryError,
+NotADirectoryError,
+BrokenPipeError,
+ ):
 return-1
-except(ValueError, OSError)ase:
+exceptValueErrorase:
 expected_messages= [
 "SHA is empty",
 "Reference at",
 "embedded null byte",
 "This submodule instance does not exist anymore",
 "cmd stdin was empty",
-"File name too long",
  ]
 ifis_expected_exception_message(e, expected_messages):
 return-1
@@ -85,6 +102,7 @@ def TestOneInput(data):
 
 
 defmain():
+atheris.instrument_all()
 atheris.Setup(sys.argv, TestOneInput)
 atheris.Fuzz()
 

fuzzing/fuzz-targets/utils.py

@@ -1,4 +1,5 @@
 importatheris# pragma: no cover
+importos# pragma: no cover
 fromtypingimportList# pragma: no cover
 
 
@@ -20,3 +21,17 @@ def is_expected_exception_message(exception: Exception, error_message_list: List
 iferror.lower() inexception_message:
 returnTrue
 returnFalse
+
+
+@atheris.instrument_func
+defget_max_filename_length(path: str) ->int: # pragma: no cover
+"""
+ Get the maximum filename length for the filesystem containing the given path.
+
+ Args:
+ path (str): The path to check the filesystem for.
+
+ Returns:
+ int: The maximum filename length.
+ """
+returnos.pathconf(path, "PC_NAME_MAX")