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gh-118209: Add Windows structured exception handling to mmap module (GH-118213) 

(cherry picked from commit e85e8deaf3)

Co-authored-by: Dobatymo <Dobatymo@users.noreply.github.com>
This commit is contained in:
Miss Islington (bot) 2024-05-10 13:00:00 +02:00 committed by GitHub
parent 760b3f08dc
commit 7dc9875d55
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GPG Key ID: B5690EEEBB952194
4 changed files with 410 additions and 48 deletions
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3
Doc/whatsnew/3.13.rst
View File

@ -796,6 +796,9 @@ mmap
* :class:`mmap.mmap` now has a *trackfd* parameter on Unix; if it is ``False``,
the file descriptor specified by *fileno* will not be duplicated.
(Contributed by Zackery Spytz and Petr Viktorin in :gh:`78502`.)
* :class:`mmap.mmap` is now protected from crashing on Windows when the mapped memory
is inaccessible due to file system errors or access violations.
(Contributed by Jannis Weigend in :gh:`118209`.)
opcode
------

77
Lib/test/test_mmap.py
View File

@ -3,6 +3,7 @@ from test.support import (
)
from test.support.import_helper import import_module
from test.support.os_helper import TESTFN, unlink
from test.support.script_helper import assert_python_ok
import unittest
import errno
import os
@ -12,6 +13,7 @@ import random
import socket
import string
import sys
import textwrap
import weakref
# Skip test if we can't import mmap.
@ -1058,6 +1060,81 @@ class MmapTests(unittest.TestCase):
with self.assertRaisesRegex(ValueError, "mmap closed or invalid"):
m.write_byte(X())
@unittest.skipUnless(os.name == 'nt', 'requires Windows')
@unittest.skipUnless(hasattr(mmap.mmap, '_protect'), 'test needs debug build')
def test_access_violations(self):
from test.support.os_helper import TESTFN
code = textwrap.dedent("""
import faulthandler
import mmap
import os
import sys
from contextlib import suppress
# Prevent logging access violations to stderr.
faulthandler.disable()
PAGESIZE = mmap.PAGESIZE
PAGE_NOACCESS = 0x01
with open(sys.argv[1], 'bw+') as f:
f.write(b'A'* PAGESIZE)
f.flush()
m = mmap.mmap(f.fileno(), PAGESIZE)
m._protect(PAGE_NOACCESS, 0, PAGESIZE)
with suppress(OSError):
m.read(PAGESIZE)
assert False, 'mmap.read() did not raise'
with suppress(OSError):
m.read_byte()
assert False, 'mmap.read_byte() did not raise'
with suppress(OSError):
m.readline()
assert False, 'mmap.readline() did not raise'
with suppress(OSError):
m.write(b'A'* PAGESIZE)
assert False, 'mmap.write() did not raise'
with suppress(OSError):
m.write_byte(0)
assert False, 'mmap.write_byte() did not raise'
with suppress(OSError):
m[0] # test mmap_subscript
assert False, 'mmap.__getitem__() did not raise'
with suppress(OSError):
m[0:10] # test mmap_subscript
assert False, 'mmap.__getitem__() did not raise'
with suppress(OSError):
m[0:10:2] # test mmap_subscript
assert False, 'mmap.__getitem__() did not raise'
with suppress(OSError):
m[0] = 1
assert False, 'mmap.__setitem__() did not raise'
with suppress(OSError):
m[0:10] = b'A'* 10
assert False, 'mmap.__setitem__() did not raise'
with suppress(OSError):
m[0:10:2] = b'A'* 5
assert False, 'mmap.__setitem__() did not raise'
with suppress(OSError):
m.move(0, 10, 1)
assert False, 'mmap.move() did not raise'
with suppress(OSError):
list(m) # test mmap_item
assert False, 'mmap.__getitem__() did not raise'
with suppress(OSError):
m.find(b'A')
assert False, 'mmap.find() did not raise'
with suppress(OSError):
m.rfind(b'A')
assert False, 'mmap.rfind() did not raise'
""")
rt, stdout, stderr = assert_python_ok("-c", code, TESTFN)
self.assertEqual(stdout.strip(), b'')
self.assertEqual(stderr.strip(), b'')
class LargeMmapTests(unittest.TestCase):
def setUp(self):

2
Misc/NEWS.d/next/Windows/2024-04-24-05-16-32.gh-issue-118209.Ryyzlz.rst Normal file
View File

@ -0,0 +1,2 @@
Avoid crashing in :mod:`mmap` on Windows when the mapped memory is inaccessible
due to file system errors or access violations.

376
Modules/mmapmodule.c
View File

@ -41,6 +41,7 @@
#ifdef MS_WINDOWS
#include <windows.h>
#include <ntsecapi.h> // LsaNtStatusToWinError
static int
my_getpagesize(void)
{
@ -255,6 +256,208 @@ do { \
} while (0)
#endif /* UNIX */
#if defined(MS_WINDOWS) && !defined(DONT_USE_SEH)
static DWORD
filter_page_exception(EXCEPTION_POINTERS *ptrs, EXCEPTION_RECORD *record)
{
*record = *ptrs->ExceptionRecord;
if (record->ExceptionCode == EXCEPTION_IN_PAGE_ERROR ||
record->ExceptionCode == EXCEPTION_ACCESS_VIOLATION)
{
return EXCEPTION_EXECUTE_HANDLER;
}
return EXCEPTION_CONTINUE_SEARCH;
}
static DWORD
filter_page_exception_method(mmap_object *self, EXCEPTION_POINTERS *ptrs,
EXCEPTION_RECORD *record)
{
*record = *ptrs->ExceptionRecord;
if (record->ExceptionCode == EXCEPTION_IN_PAGE_ERROR ||
record->ExceptionCode == EXCEPTION_ACCESS_VIOLATION)
{
ULONG_PTR address = record->ExceptionInformation[1];
if (address >= (ULONG_PTR) self->data &&
address < (ULONG_PTR) self->data + (ULONG_PTR) self->size)
{
return EXCEPTION_EXECUTE_HANDLER;
}
}
return EXCEPTION_CONTINUE_SEARCH;
}
#endif
#if defined(MS_WINDOWS) && !defined(DONT_USE_SEH)
#define HANDLE_INVALID_MEM(sourcecode) \
do { \
EXCEPTION_RECORD record; \
__try { \
sourcecode \
} \
__except (filter_page_exception(GetExceptionInformation(), &record)) { \
assert(record.ExceptionCode == EXCEPTION_IN_PAGE_ERROR || \
record.ExceptionCode == EXCEPTION_ACCESS_VIOLATION); \
if (record.ExceptionCode == EXCEPTION_IN_PAGE_ERROR) { \
NTSTATUS status = (NTSTATUS) record.ExceptionInformation[2]; \
ULONG code = LsaNtStatusToWinError(status); \
PyErr_SetFromWindowsErr(code); \
} \
else if (record.ExceptionCode == EXCEPTION_ACCESS_VIOLATION) { \
PyErr_SetFromWindowsErr(ERROR_NOACCESS); \
} \
return -1; \
} \
} while (0)
#else
#define HANDLE_INVALID_MEM(sourcecode) \
do { \
sourcecode \
} while (0)
#endif
#if defined(MS_WINDOWS) && !defined(DONT_USE_SEH)
#define HANDLE_INVALID_MEM_METHOD(self, sourcecode) \
do { \
EXCEPTION_RECORD record; \
__try { \
sourcecode \
} \
__except (filter_page_exception_method(self, GetExceptionInformation(), \
&record)) { \
assert(record.ExceptionCode == EXCEPTION_IN_PAGE_ERROR || \
record.ExceptionCode == EXCEPTION_ACCESS_VIOLATION); \
if (record.ExceptionCode == EXCEPTION_IN_PAGE_ERROR) { \
NTSTATUS status = (NTSTATUS) record.ExceptionInformation[2]; \
ULONG code = LsaNtStatusToWinError(status); \
PyErr_SetFromWindowsErr(code); \
} \
else if (record.ExceptionCode == EXCEPTION_ACCESS_VIOLATION) { \
PyErr_SetFromWindowsErr(ERROR_NOACCESS); \
} \
return -1; \
} \
} while (0)
#else
#define HANDLE_INVALID_MEM_METHOD(self, sourcecode) \
do { \
sourcecode \
} while (0)
#endif
int
safe_memcpy(void *dest, const void *src, size_t count)
{
HANDLE_INVALID_MEM(
memcpy(dest, src, count);
);
return 0;
}
int
safe_byte_copy(char *dest, const char *src)
{
HANDLE_INVALID_MEM(
*dest = *src;
);
return 0;
}
int
safe_memchr(char **out, const void *ptr, int ch, size_t count)
{
HANDLE_INVALID_MEM(
*out = (char *) memchr(ptr, ch, count);
);
return 0;
}
int
safe_memmove(void *dest, const void *src, size_t count)
{
HANDLE_INVALID_MEM(
memmove(dest, src, count);
);
return 0;
}
int
safe_copy_from_slice(char *dest, const char *src, Py_ssize_t start,
Py_ssize_t step, Py_ssize_t slicelen)
{
HANDLE_INVALID_MEM(
size_t cur;
Py_ssize_t i;
for (cur = start, i = 0; i < slicelen; cur += step, i++) {
dest[cur] = src[i];
}
);
return 0;
}
int
safe_copy_to_slice(char *dest, const char *src, Py_ssize_t start,
Py_ssize_t step, Py_ssize_t slicelen)
{
HANDLE_INVALID_MEM(
size_t cur;
Py_ssize_t i;
for (cur = start, i = 0; i < slicelen; cur += step, i++) {
dest[i] = src[cur];
}
);
return 0;
}
int
_safe_PyBytes_Find(Py_ssize_t *out, mmap_object *self, const char *haystack,
Py_ssize_t len_haystack, const char *needle,
Py_ssize_t len_needle, Py_ssize_t offset)
{
HANDLE_INVALID_MEM_METHOD(self,
*out = _PyBytes_Find(haystack, len_haystack, needle, len_needle, offset);
);
return 0;
}
int
_safe_PyBytes_ReverseFind(Py_ssize_t *out, mmap_object *self,
const char *haystack, Py_ssize_t len_haystack,
const char *needle, Py_ssize_t len_needle,
Py_ssize_t offset)
{
HANDLE_INVALID_MEM_METHOD(self,
*out = _PyBytes_ReverseFind(haystack, len_haystack, needle, len_needle,
offset);
);
return 0;
}
PyObject *
_safe_PyBytes_FromStringAndSize(char *start, size_t num_bytes) {
if (num_bytes == 1) {
char dest;
if (safe_byte_copy(&dest, start) < 0) {
return NULL;
}
else {
return PyBytes_FromStringAndSize(&dest, 1);
}
}
else {
PyObject *result = PyBytes_FromStringAndSize(NULL, num_bytes);
if (result == NULL) {
return NULL;
}
if (safe_memcpy(PyBytes_AS_STRING(result), start, num_bytes) < 0) {
Py_CLEAR(result);
}
return result;
}
}
static PyObject *
mmap_read_byte_method(mmap_object *self,
PyObject *Py_UNUSED(ignored))
@ -264,7 +467,12 @@ mmap_read_byte_method(mmap_object *self,
PyErr_SetString(PyExc_ValueError, "read byte out of range");
return NULL;
}
return PyLong_FromLong((unsigned char)self->data[self->pos++]);
char dest;
if (safe_byte_copy(&dest, self->data + self->pos) < 0) {
return NULL;
}
self->pos++;
return PyLong_FromLong((unsigned char) dest);
}
static PyObject *
@ -273,7 +481,6 @@ mmap_read_line_method(mmap_object *self,
{
Py_ssize_t remaining;
char *start, *eol;
PyObject *result;
CHECK_VALID(NULL);
@ -281,13 +488,20 @@ mmap_read_line_method(mmap_object *self,
if (!remaining)
return PyBytes_FromString("");
start = self->data + self->pos;
eol = memchr(start, '\n', remaining);
if (safe_memchr(&eol, start, '\n', remaining) < 0) {
return NULL;
}
if (!eol)
eol = self->data + self->size;
else
++eol; /* advance past newline */
result = PyBytes_FromStringAndSize(start, (eol - start));
self->pos += (eol - start);
PyObject *result = _safe_PyBytes_FromStringAndSize(start, eol - start);
if (result != NULL) {
self->pos += (eol - start);
}
return result;
}
@ -296,7 +510,6 @@ mmap_read_method(mmap_object *self,
PyObject *args)
{
Py_ssize_t num_bytes = PY_SSIZE_T_MAX, remaining;
PyObject *result;
CHECK_VALID(NULL);
if (!PyArg_ParseTuple(args, "|O&:read", _Py_convert_optional_to_ssize_t, &num_bytes))
@ -307,8 +520,12 @@ mmap_read_method(mmap_object *self,
remaining = (self->pos < self->size) ? self->size - self->pos : 0;
if (num_bytes < 0 || num_bytes > remaining)
num_bytes = remaining;
result = PyBytes_FromStringAndSize(&self->data[self->pos], num_bytes);
self->pos += num_bytes;
PyObject *result = _safe_PyBytes_FromStringAndSize(self->data + self->pos,
num_bytes);
if (result != NULL) {
self->pos += num_bytes;
}
return result;
}
@ -341,25 +558,38 @@ mmap_gfind(mmap_object *self,
else if (end > self->size)
end = self->size;
Py_ssize_t res;
Py_ssize_t index;
PyObject *result;
CHECK_VALID_OR_RELEASE(NULL, view);
if (end < start) {
res = -1;
result = PyLong_FromSsize_t(-1);
}
else if (reverse) {
assert(0 <= start && start <= end && end <= self->size);
res = _PyBytes_ReverseFind(
if (_safe_PyBytes_ReverseFind(&index, self,
self->data + start, end - start,
view.buf, view.len, start);
view.buf, view.len, start) < 0)
{
result = NULL;
}
else {
result = PyLong_FromSsize_t(index);
}
}
else {
assert(0 <= start && start <= end && end <= self->size);
res = _PyBytes_Find(
if (_safe_PyBytes_Find(&index, self,
self->data + start, end - start,
view.buf, view.len, start);
view.buf, view.len, start) < 0)
{
result = NULL;
}
else {
result = PyLong_FromSsize_t(index);
}
}
PyBuffer_Release(&view);
return PyLong_FromSsize_t(res);
return result;
}
}
@ -432,10 +662,16 @@ mmap_write_method(mmap_object *self,
}
CHECK_VALID_OR_RELEASE(NULL, data);
memcpy(&self->data[self->pos], data.buf, data.len);
self->pos += data.len;
PyObject *result;
if (safe_memcpy(self->data + self->pos, data.buf, data.len) < 0) {
result = NULL;
}
else {
self->pos += data.len;
result = PyLong_FromSsize_t(data.len);
}
PyBuffer_Release(&data);
return PyLong_FromSsize_t(data.len);
return result;
}
static PyObject *
@ -452,14 +688,16 @@ mmap_write_byte_method(mmap_object *self,
return NULL;
CHECK_VALID(NULL);
if (self->pos < self->size) {
self->data[self->pos++] = value;
Py_RETURN_NONE;
}
else {
if (self->pos >= self->size) {
PyErr_SetString(PyExc_ValueError, "write byte out of range");
return NULL;
}
if (safe_byte_copy(self->data + self->pos, &value) < 0) {
return NULL;
}
self->pos++;
Py_RETURN_NONE;
}
static PyObject *
@ -763,8 +1001,9 @@ mmap_move_method(mmap_object *self, PyObject *args)
goto bounds;
CHECK_VALID(NULL);
memmove(&self->data[dest], &self->data[src], cnt);
if (safe_memmove(self->data + dest, self->data + src, cnt) < 0) {
return NULL;
};
Py_RETURN_NONE;
bounds:
@ -855,6 +1094,29 @@ mmap__sizeof__method(mmap_object *self, void *Py_UNUSED(ignored))
}
#endif
#if defined(MS_WINDOWS) && defined(Py_DEBUG)
static PyObject *
mmap_protect_method(mmap_object *self, PyObject *args) {
DWORD flNewProtect, flOldProtect;
Py_ssize_t start, length;
CHECK_VALID(NULL);
if (!PyArg_ParseTuple(args, "Inn:protect", &flNewProtect, &start, &length)) {
return NULL;
}
if (!VirtualProtect((void *) (self->data + start), length, flNewProtect,
&flOldProtect))
{
PyErr_SetFromWindowsErr(GetLastError());
return NULL;
}
Py_RETURN_NONE;
}
#endif
#ifdef HAVE_MADVISE
static PyObject *
mmap_madvise_method(mmap_object *self, PyObject *args)
@ -924,7 +1186,10 @@ static struct PyMethodDef mmap_object_methods[] = {
{"__exit__", (PyCFunction) mmap__exit__method, METH_VARARGS},
#ifdef MS_WINDOWS
{"__sizeof__", (PyCFunction) mmap__sizeof__method, METH_NOARGS},
#endif
#ifdef Py_DEBUG
{"_protect", (PyCFunction) mmap_protect_method, METH_VARARGS},
#endif // Py_DEBUG
#endif // MS_WINDOWS
{NULL, NULL} /* sentinel */
};
@ -968,7 +1233,12 @@ mmap_item(mmap_object *self, Py_ssize_t i)
PyErr_SetString(PyExc_IndexError, "mmap index out of range");
return NULL;
}
return PyBytes_FromStringAndSize(self->data + i, 1);
char dest;
if (safe_byte_copy(&dest, self->data + i) < 0) {
return NULL;
}
return PyBytes_FromStringAndSize(&dest, 1);
}
static PyObject *
@ -987,7 +1257,12 @@ mmap_subscript(mmap_object *self, PyObject *item)
return NULL;
}
CHECK_VALID(NULL);
return PyLong_FromLong(Py_CHARMASK(self->data[i]));
char dest;
if (safe_byte_copy(&dest, self->data + i) < 0) {
return NULL;
}
return PyLong_FromLong(Py_CHARMASK(dest));
}
else if (PySlice_Check(item)) {
Py_ssize_t start, stop, step, slicelen;
@ -1001,23 +1276,22 @@ mmap_subscript(mmap_object *self, PyObject *item)
if (slicelen <= 0)
return PyBytes_FromStringAndSize("", 0);
else if (step == 1)
return PyBytes_FromStringAndSize(self->data + start,
slicelen);
return _safe_PyBytes_FromStringAndSize(self->data + start, slicelen);
else {
char *result_buf = (char *)PyMem_Malloc(slicelen);
size_t cur;
Py_ssize_t i;
PyObject *result;
if (result_buf == NULL)
return PyErr_NoMemory();
for (cur = start, i = 0; i < slicelen;
cur += step, i++) {
result_buf[i] = self->data[cur];
if (safe_copy_to_slice(result_buf, self->data, start, step,
slicelen) < 0)
{
result = NULL;
}
else {
result = PyBytes_FromStringAndSize(result_buf, slicelen);
}
result = PyBytes_FromStringAndSize(result_buf,
slicelen);
PyMem_Free(result_buf);
return result;
}
@ -1052,7 +1326,10 @@ mmap_ass_item(mmap_object *self, Py_ssize_t i, PyObject *v)
if (!is_writable(self))
return -1;
buf = PyBytes_AsString(v);
self->data[i] = buf[0];
if (safe_byte_copy(self->data + i, buf) < 0) {
return -1;
}
return 0;
}
@ -1097,7 +1374,11 @@ mmap_ass_subscript(mmap_object *self, PyObject *item, PyObject *value)
return -1;
}
CHECK_VALID(-1);
self->data[i] = (char) v;
char v_char = (char) v;
if (safe_byte_copy(self->data + i, &v_char) < 0) {
return -1;
}
return 0;
}
else if (PySlice_Check(item)) {
@ -1123,24 +1404,23 @@ mmap_ass_subscript(mmap_object *self, PyObject *item, PyObject *value)
}
CHECK_VALID_OR_RELEASE(-1, vbuf);
int result = 0;
if (slicelen == 0) {
}
else if (step == 1) {
memcpy(self->data + start, vbuf.buf, slicelen);
if (safe_memcpy(self->data + start, vbuf.buf, slicelen) < 0) {
result = -1;
}
}
else {
size_t cur;
Py_ssize_t i;
for (cur = start, i = 0;
i < slicelen;
cur += step, i++)
if (safe_copy_from_slice(self->data, (char *)vbuf.buf, start, step,
slicelen) < 0)
{
self->data[cur] = ((char *)vbuf.buf)[i];
result = -1;
}
}
PyBuffer_Release(&vbuf);
return 0;
return result;
}
else {
PyErr_SetString(PyExc_TypeError,