summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorRichard Oudkerk <shibturn@gmail.com>2013-02-13 12:18:03 (GMT)
committerRichard Oudkerk <shibturn@gmail.com>2013-02-13 12:18:03 (GMT)
commit0d09ba8e0bc57b50984d1968aab3c29de3e1320d (patch)
treea91dea1de06d69f47b0ba922c4b46467b6f7c15a
parent7e0191170e95ffd9c95d840a5631e0f1831998f9 (diff)
downloadcpython-0d09ba8e0bc57b50984d1968aab3c29de3e1320d.zip
cpython-0d09ba8e0bc57b50984d1968aab3c29de3e1320d.tar.gz
cpython-0d09ba8e0bc57b50984d1968aab3c29de3e1320d.tar.bz2
Issue #16743: Fix mmap overflow check on 32 bit Windows
-rw-r--r--Lib/test/test_mmap.py7
-rw-r--r--Modules/mmapmodule.c22
2 files changed, 18 insertions, 11 deletions
diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py
index 28b52a9..4407c5c 100644
--- a/Lib/test/test_mmap.py
+++ b/Lib/test/test_mmap.py
@@ -693,6 +693,13 @@ class LargeMmapTests(unittest.TestCase):
def test_large_filesize(self):
with self._make_test_file(0x17FFFFFFF, b" ") as f:
+ if sys.maxsize < 0x180000000:
+ # On 32 bit platforms the file is larger than sys.maxsize so
+ # mapping the whole file should fail -- Issue #16743
+ with self.assertRaises(OverflowError):
+ mmap.mmap(f.fileno(), 0x180000000, access=mmap.ACCESS_READ)
+ with self.assertRaises(ValueError):
+ mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ)
with mmap.mmap(f.fileno(), 0x10000, access=mmap.ACCESS_READ) as m:
self.assertEqual(m.size(), 0x180000000)
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index 33c143e..352dd52 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -1140,7 +1140,6 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict)
# endif
if (fd != -1 && fstat(fd, &st) == 0 && S_ISREG(st.st_mode)) {
if (map_size == 0) {
- off_t calc_size;
if (st.st_size == 0) {
PyErr_SetString(PyExc_ValueError,
"cannot mmap an empty file");
@@ -1151,13 +1150,12 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict)
"mmap offset is greater than file size");
return NULL;
}
- calc_size = st.st_size - offset;
- map_size = calc_size;
- if (map_size != calc_size) {
+ if (st.st_size - offset > PY_SSIZE_T_MAX) {
PyErr_SetString(PyExc_ValueError,
"mmap length is too large");
- return NULL;
- }
+ return NULL;
+ }
+ map_size = (Py_ssize_t) (st.st_size - offset);
} else if (offset + (size_t)map_size > st.st_size) {
PyErr_SetString(PyExc_ValueError,
"mmap length is greater than file size");
@@ -1354,11 +1352,13 @@ new_mmap_object(PyTypeObject *type, PyObject *args, PyObject *kwdict)
Py_DECREF(m_obj);
return NULL;
}
- if (offset - size > PY_SSIZE_T_MAX)
- /* Map area too large to fit in memory */
- m_obj->size = (Py_ssize_t) -1;
- else
- m_obj->size = (Py_ssize_t) (size - offset);
+ if (size - offset > PY_SSIZE_T_MAX) {
+ PyErr_SetString(PyExc_ValueError,
+ "mmap length is too large");
+ Py_DECREF(m_obj);
+ return NULL;
+ }
+ m_obj->size = (Py_ssize_t) (size - offset);
} else {
m_obj->size = map_size;
size = offset + map_size;