narrow_widen_acl: enforce narrowacl in narrow_widen (SEC)
Reviewer note: this was sent by the author as a simple bugfix, but can be
considered a security patch, since it allows users to access things outside
of the ACL, hence the (SEC) prefix.
However, this affects the `narrow` extention which is still marked as
experimental and has relatively few users aside from large companies with
their own security layers on top from what we can gather.
We feel (Alphare: or at least, I feel) like pinging the packaging list is
enough in this case.
#include <Python.h>
#include <assert.h>
#include <stdlib.h>
#include <unistd.h>
#include "pyutil.h"
#include <iostream>
#include <string>
extern "C" {
static PYCODETYPE *code;
extern "C" int LLVMFuzzerInitialize(int *argc, char ***argv)
{
contrib::initpy(*argv[0]);
code = (PYCODETYPE *)Py_CompileString(R"py(
try:
for fn in (
parsers.isasciistr,
parsers.asciilower,
parsers.asciiupper,
parsers.encodedir,
parsers.pathencode,
parsers.lowerencode,
):
try:
fn(data)
except UnicodeDecodeError:
pass # some functions emit this exception
except AttributeError:
# pathencode needs hashlib, which fails to import because the time
# module fails to import. We should try and fix that some day, but
# for now we at least get coverage on non-hashencoded codepaths.
if fn != pathencode:
raise
# uncomment this for debugging exceptions
# except Exception as e:
# raise Exception('%r: %r' % (fn, e))
except Exception as e:
pass
# uncomment this print if you're editing this Python code
# to debug failures.
# print(e)
)py",
"fuzzer", Py_file_input);
if (!code) {
std::cerr << "failed to compile Python code!" << std::endl;
}
return 0;
}
int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)
{
PyObject *mtext =
PyBytes_FromStringAndSize((const char *)Data, (Py_ssize_t)Size);
PyObject *locals = PyDict_New();
PyDict_SetItemString(locals, "data", mtext);
PyObject *res = PyEval_EvalCode(code, contrib::pyglobals(), locals);
if (!res) {
PyErr_Print();
}
Py_XDECREF(res);
Py_DECREF(locals);
Py_DECREF(mtext);
return 0; // Non-zero return values are reserved for future use.
}
}