8000 gh-132909: handle overflow for 'K' format in `do_mkvalue` by picnixz · Pull Request #132911 · python/cpython · GitHub
[go: up one dir, main page]
Skip to content

gh-132909: handle overflow for 'K' format in do_mkvalue #132911

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

Merged
merged 3 commits into from
Apr 25, 2025
Merged

gh-132909: handle overflow for 'K' format in do_mkvalue #132911

Show file tree
Hide file tree
Changes from 2 commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
a3caf1b
handle overflows for 'K' and 'u' formats in `do_mkvalue`
picnixz Apr 10, 2025
f74214c
fix(docs)
picnixz Apr 25, 2025
80fd7f7
reduce diff
picnixz Apr 25, 2025
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
4 changes: 4 additions & 0 deletions Doc/c-api/arg.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -626,6 +626,8 @@ Building values
``z#`` (:class:`str` or ``None``) [const char \*, :c:type:`Py_ssize_t`]
Same as ``s#``.

.. _capi-py-buildvalue-format-u:

``u`` (:class:`str`) [const wchar_t \*]
Convert a null-terminated :c:type:`wchar_t` buffer of Unicode (UTF-16 or UCS-4)
data to a Python Unicode object. If the Unicode buffer pointer is ``NULL``,
Expand Down Expand Up @@ -669,6 +671,8 @@ Building values
``L`` (:class:`int`) [long long]
Convert a C :c:expr:`long long` to a Python integer object.

.. _capi-py-buildvalue-format-K:

``K`` (:class:`int`) [unsigned long long]
Convert a C :c:expr:`unsigned long long` to a Python integer object.

Expand Down
3 changes: 3 additions & 0 deletions Misc/NEWS.d/next/C_API/2025-04-25-11-39-24.gh-issue-132909.JC3n_l.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,3 @@
Fix overflows when handling :ref:`K <capi-py-buildvalue-format-K>` and
:ref:`u <capi-py-buildvalue-format-u>` formats in :c:func:`Py_BuildValue`.
Patch by Bénédikt Tran.
71 changes: 47 additions & 24 deletions Python/modsupport.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -268,6 +268,30 @@ do_mktuple(const char **p_format, va_list *p_va, char endchar, Py_ssize_t n)
return v;
}

static Py_ssize_t
safe_strlen(const char *u)
{
size_t m = strlen(u);
if (m > PY_SSIZE_T_MAX) {
PyErr_SetString(PyExc_OverflowError,
"string too long for Python string");
return -1;
}
return (Py_ssize_t)m;
}

static Py_ssize_t
safe_wcslen(const wchar_t *u)
{
size_t m = wcslen(u);
if (m > PY_SSIZE_T_MAX) {
PyErr_SetString(PyExc_OverflowError,
"string too long for Python string");
return -1;
}
return (Py_ssize_t)m;
}

static PyObject *
do_mkvalue(const char **p_format, va_list *p_va)
{
Expand Down Expand Up @@ -318,32 +342,41 @@ do_mkvalue(const char **p_format, va_list *p_va)
}

case 'L':
return PyLong_FromLongLong((long long)va_arg(*p_va, long long));
{
long long v = va_arg(*p_va, long long);
return PyLong_FromLongLong(v);
}

case 'K':
return PyLong_FromUnsignedLongLong((long long)va_arg(*p_va, unsigned long long));
{
unsigned long long v = va_arg(*p_va, unsigned long long);
return PyLong_FromUnsignedLongLong(v);
}

case 'u':
{
PyObject *v;
const wchar_t *u = va_arg(*p_va, wchar_t*);
Py_ssize_t n;
const wchar_t *u = va_arg(*p_va, const wchar_t *);
Py_ssize_t n = -1;
if (**p_format == '#') {
++*p_format;
n = va_arg(*p_va, Py_ssize_t);
}
else
n = -1;
if (u == NULL) {
v = Py_NewRef(Py_None);
}
else {
if (n < 0)
n = wcslen(u);
if (n < 0) {
n = safe_wcslen(u);
if (n < 0) {
return NULL;
}
}
v = PyUnicode_FromWideChar(u, n);
}
return v;
}

case 'f':
case 'd':
return PyFloat_FromDouble(
Expand Down Expand Up @@ -376,25 +409,20 @@ do_mkvalue(const char **p_format, va_list *p_va)
{
PyObject *v;
const char *str = va_arg(*p_va, const char *);
Py_ssize_t n;
Py_ssize_t n = -1;
if (**p_format == '#') {
++*p_format;
n = va_arg(*p_va, Py_ssize_t);
}
else
n = -1;
if (str == NULL) {
v = Py_NewRef(Py_None);
}
else {
if (n < 0) {
size_t m = strlen(str);
if (m > PY_SSIZE_T_MAX) {
PyErr_SetString(PyExc_OverflowError,
"string too long for Python string");
n = safe_strlen(str);
if (n < 0) {
return NULL;
}
n = (Py_ssize_t)m;
}
v = PyUnicode_FromStringAndSize(str, n);
}
Expand All @@ -405,25 +433,20 @@ do_mkvalue(const char **p_format, va_list *p_va)
{
PyObject *v;
const char *str = va_arg(*p_va, const char *);
Py_ssize_t n;
Py_ssize_t n = -1;
if (**p_format == '#') {
++*p_format;
n = va_arg(*p_va, Py_ssize_t);
}
else
n = -1;
if (str == NULL) {
v = Py_NewRef(Py_None);
}
else {
if (n < 0) {
size_t m = strlen(str);
if (m > PY_SSIZE_T_MAX) {
PyErr_SetString(PyExc_OverflowError,
"string too long for Python bytes");
n = safe_strlen(str);
if (n < 0) {
return NULL;
}
n = (Py_ssize_t)m;
}
v = PyBytes_FromStringAndSize(str, n);
}
Expand Down
Loading
0