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Differential D4906

fuzzers: init Python in LLVMFuzzerInitialize and intentionally leak it
ClosedPublic

Authored by durin42 on Oct 8 2018, 12:09 PM.

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rHG3418f83c8874: fuzzers: init Python in LLVMFuzzerInitialize and intentionally leak it
Summary

This sidesteps leaks (or "leaks", I'm not sure) in CPython, and lets
our fuzzer work.

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Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

durin42 created this revision.Oct 8 2018, 12:09 PM
Closed by commit rHG3418f83c8874: fuzzers: init Python in LLVMFuzzerInitialize and intentionally leak it (authored by durin42). · Explain WhyOct 8 2018, 12:26 PM
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mcontrib/fuzz/manifest.cc (3 lines)

Diff 11744

contrib/fuzz/manifest.cc

getcwd(wd, 8192); getcwd(wd, 8192);
pypath = std::string(wd) + subdir; pypath = std::string(wd) + subdir;
} else { } else {
pypath = selfpath.substr(0, pos) + subdir; pypath = selfpath.substr(0, pos) + subdir;
} }
strncpy(cpypath, pypath.c_str(), pypath.size()); strncpy(cpypath, pypath.c_str(), pypath.size());
setenv("PYTHONPATH", cpypath, 1); setenv("PYTHONPATH", cpypath, 1);
Py_SetPythonHome(cpypath); Py_SetPythonHome(cpypath);
Py_InitializeEx(0);
return 0; return 0;
} }
int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
{ {
Py_InitializeEx(0);
initparsers(); initparsers();
PyObject *mtext = PyObject *mtext =
PyBytes_FromStringAndSize((const char *)Data, (Py_ssize_t)Size); PyBytes_FromStringAndSize((const char *)Data, (Py_ssize_t)Size);
PyObject *mainmod = PyImport_AddModule("__main__"); PyObject *mainmod = PyImport_AddModule("__main__");
PyObject *globals = PyModule_GetDict(mainmod); PyObject *globals = PyModule_GetDict(mainmod);
PyObject *locals = PyDict_New(); PyObject *locals = PyDict_New();
PyDict_SetItemString(locals, "mdata", mtext); PyDict_SetItemString(locals, "mdata", mtext);
PyCodeObject *code = PyCodeObject *code =
# to debug failures. # to debug failures.
# print e # print e
)py", )py",
"fuzzer", Py_file_input); "fuzzer", Py_file_input);
PyEval_EvalCode(code, globals, locals); PyEval_EvalCode(code, globals, locals);
Py_DECREF(code); Py_DECREF(code);
Py_DECREF(locals); Py_DECREF(locals);
Py_DECREF(mtext); Py_DECREF(mtext);
Py_Finalize();
return 0; // Non-zero return values are reserved for future use. return 0; // Non-zero return values are reserved for future use.
} }
} }