Merged revisions 64114 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
........
r64114 | gregory.p.smith | 2008-06-11 09:41:16 +0200 (mer., 11 juin 2008) | 6 lines
Merge in release25-maint r60793:
Added checks for integer overflows, contributed by Google. Some are
only available if asserts are left in the code, in cases where they
can't be triggered from Python code.
........
diff --git a/Objects/listobject.c b/Objects/listobject.c
index d5f3a19..255f087 100644
--- a/Objects/listobject.c
+++ b/Objects/listobject.c
@@ -45,7 +45,16 @@
* system realloc().
* The growth pattern is: 0, 4, 8, 16, 25, 35, 46, 58, 72, 88, ...
*/
- new_allocated = (newsize >> 3) + (newsize < 9 ? 3 : 6) + newsize;
+ new_allocated = (newsize >> 3) + (newsize < 9 ? 3 : 6);
+
+ /* check for integer overflow */
+ if (new_allocated > PY_SIZE_MAX - newsize) {
+ PyErr_NoMemory();
+ return -1;
+ } else {
+ new_allocated += newsize;
+ }
+
if (newsize == 0)
new_allocated = 0;
items = self->ob_item;
@@ -118,8 +127,9 @@
return NULL;
}
nbytes = size * sizeof(PyObject *);
- /* Check for overflow */
- if (nbytes / sizeof(PyObject *) != (size_t)size)
+ /* Check for overflow without an actual overflow,
+ * which can cause compiler to optimise out */
+ if (size > PY_SIZE_MAX / sizeof(PyObject *))
return PyErr_NoMemory();
if (numfree) {
numfree--;
@@ -1323,6 +1333,10 @@
* we don't care what's in the block.
*/
merge_freemem(ms);
+ if (need > PY_SSIZE_T_MAX / sizeof(PyObject*)) {
+ PyErr_NoMemory();
+ return -1;
+ }
ms->a = (PyObject **)PyMem_Malloc(need * sizeof(PyObject*));
if (ms->a) {
ms->alloced = need;
@@ -2415,6 +2429,8 @@
step = -step;
}
+ assert(slicelength <= PY_SIZE_MAX / sizeof(PyObject*));
+
garbage = (PyObject**)
PyMem_MALLOC(slicelength*sizeof(PyObject*));
if (!garbage) {