[3.11] gh-106844: Fix issues in _winapi.LCMapStringEx (GH-107832) (GH-107875)

* Strings with length from 2**31-1 to 2**32-2 always caused MemoryError,
   it doesn't matter how much memory is available.
* Strings with length exactly 2**32-1 caused OSError.
* Strings longer than 2**32-1 characters were truncated due to integer overflow bug.

Now strings longer than 2**31-1 characters caused OverflowError.
(cherry picked from commit 04cc01453d)
This commit is contained in:
Serhiy Storchaka 2023-08-12 14:06:56 +03:00 committed by GitHub
parent 4ddfb04260
commit ec254c5dfa
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3 changed files with 19 additions and 15 deletions

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@ -908,6 +908,7 @@ def test_path_normcase(self):
self._check_function(self.path.normcase)
if sys.platform == 'win32':
self.assertEqual(ntpath.normcase('\u03a9\u2126'), 'ωΩ')
self.assertEqual(ntpath.normcase('abc\x00def'), 'abc\x00def')
def test_path_isabs(self):
self._check_function(self.path.isabs)

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@ -0,0 +1 @@
Fix integer overflow in :func:`!_winapi.LCMapStringEx` which affects :func:`ntpath.normcase`.

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@ -1571,24 +1571,26 @@ _winapi_LCMapStringEx_impl(PyObject *module, PyObject *locale, DWORD flags,
if (!locale_) {
return NULL;
}
Py_ssize_t srcLenAsSsize;
int srcLen;
wchar_t *src_ = PyUnicode_AsWideCharString(src, &srcLenAsSsize);
Py_ssize_t src_size;
wchar_t *src_ = PyUnicode_AsWideCharString(src, &src_size);
if (!src_) {
PyMem_Free(locale_);
return NULL;
}
srcLen = (int)srcLenAsSsize;
if (srcLen != srcLenAsSsize) {
srcLen = -1;
}
int dest_size = LCMapStringEx(locale_, flags, src_, srcLen, NULL, 0,
NULL, NULL, 0);
if (dest_size == 0) {
if (src_size > INT_MAX) {
PyMem_Free(locale_);
PyMem_Free(src_);
return PyErr_SetFromWindowsErr(0);
PyErr_SetString(PyExc_OverflowError, "input string is too long");
return NULL;
}
int dest_size = LCMapStringEx(locale_, flags, src_, (int)src_size, NULL, 0,
NULL, NULL, 0);
if (dest_size <= 0) {
DWORD error = GetLastError();
PyMem_Free(locale_);
PyMem_Free(src_);
return PyErr_SetFromWindowsErr(error);
}
wchar_t* dest = PyMem_NEW(wchar_t, dest_size);
@ -1598,9 +1600,9 @@ _winapi_LCMapStringEx_impl(PyObject *module, PyObject *locale, DWORD flags,
return PyErr_NoMemory();
}
int nmapped = LCMapStringEx(locale_, flags, src_, srcLen, dest, dest_size,
int nmapped = LCMapStringEx(locale_, flags, src_, (int)src_size, dest, dest_size,
NULL, NULL, 0);
if (nmapped == 0) {
if (nmapped <= 0) {
DWORD error = GetLastError();
PyMem_Free(locale_);
PyMem_Free(src_);
@ -1608,9 +1610,9 @@ _winapi_LCMapStringEx_impl(PyObject *module, PyObject *locale, DWORD flags,
return PyErr_SetFromWindowsErr(error);
}
PyObject *ret = PyUnicode_FromWideChar(dest, dest_size);
PyMem_Free(locale_);
PyMem_Free(src_);
PyObject *ret = PyUnicode_FromWideChar(dest, nmapped);
PyMem_DEL(dest);
return ret;