SF bug # 585792, Invalid mmap crashes Python interpreter
Raise ValueError if user passes a size to mmap which is larger
than the file.
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index 2bb6edc..cff3c14 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -850,6 +850,9 @@
static PyObject *
new_mmap_object(PyObject *self, PyObject *args, PyObject *kwdict)
{
+#ifdef HAVE_FSTAT
+ struct stat st;
+#endif
mmap_object *m_obj;
PyObject *map_size_obj = NULL;
int map_size;
@@ -890,7 +893,14 @@
return PyErr_Format(PyExc_ValueError,
"mmap invalid access parameter.");
}
-
+
+#ifdef HAVE_FSTAT
+ if (fstat(fd, &st) == 0 && (size_t)map_size > st.st_size) {
+ PyErr_SetString(PyExc_ValueError,
+ "mmap length is greater than file size");
+ return NULL;
+ }
+#endif
m_obj = PyObject_New (mmap_object, &mmap_object_type);
if (m_obj == NULL) {return NULL;}
m_obj->size = (size_t) map_size;