self.assertInBytecode(code, 'LOAD_CONST', 'b')
# Verify that large sequences do not result from folding
- code = compile('a="x"*1000', '', 'single')
+ code = compile('a="x"*10000', '', 'single')
+ self.assertInBytecode(code, 'LOAD_CONST', 10000)
+ self.assertNotIn("x"*10000, code.co_consts)
+ code = compile('a=1<<1000', '', 'single')
self.assertInBytecode(code, 'LOAD_CONST', 1000)
+ self.assertNotIn(1<<1000, code.co_consts)
+ code = compile('a=2**1000', '', 'single')
+ self.assertInBytecode(code, 'LOAD_CONST', 1000)
+ self.assertNotIn(2**1000, code.co_consts)
def test_binary_subscr_on_unicode(self):
# valid code get optimized
return maxi - 1;
}
+/* Check whether a collection doesn't containing too much items (including
+ subcollections). This protects from creating a constant that needs
+ too much time for calculating a hash.
+ "limit" is the maximal number of items.
+ Returns the negative number if the total number of items exceeds the
+ limit. Otherwise returns the limit minus the total number of items.
+*/
+
+static Py_ssize_t
+check_complexity(PyObject *obj, Py_ssize_t limit)
+{
+ if (PyTuple_Check(obj)) {
+ Py_ssize_t i;
+ limit -= PyTuple_GET_SIZE(obj);
+ for (i = 0; limit >= 0 && i < PyTuple_GET_SIZE(obj); i++) {
+ limit = check_complexity(PyTuple_GET_ITEM(obj, i), limit);
+ }
+ return limit;
+ }
+ else if (PyFrozenSet_Check(obj)) {
+ Py_ssize_t i = 0;
+ PyObject *item;
+ Py_hash_t hash;
+ limit -= PySet_GET_SIZE(obj);
+ while (limit >= 0 && _PySet_NextEntry(obj, &i, &item, &hash)) {
+ limit = check_complexity(item, limit);
+ }
+ }
+ return limit;
+}
+
/* Replace LOAD_CONST c1, LOAD_CONST c2 ... LOAD_CONST cn, BUILD_TUPLE n
with LOAD_CONST (c1, c2, ... cn).
The consts table must still be in list form so that the
return copy_op_arg(codestr, c_start, LOAD_CONST, len_consts, opcode_end);
}
+#define MAX_INT_SIZE 128 /* bits */
+#define MAX_COLLECTION_SIZE 20 /* items */
+#define MAX_STR_SIZE 20 /* characters */
+#define MAX_TOTAL_ITEMS 1024 /* including nested collections */
+
+static PyObject *
+safe_multiply(PyObject *v, PyObject *w)
+{
+ if (PyLong_Check(v) && PyLong_Check(w) && Py_SIZE(v) && Py_SIZE(w)) {
+ size_t vbits = _PyLong_NumBits(v);
+ size_t wbits = _PyLong_NumBits(w);
+ if (vbits == (size_t)-1 || wbits == (size_t)-1) {
+ return NULL;
+ }
+ if (vbits + wbits > MAX_INT_SIZE) {
+ return NULL;
+ }
+ }
+ else if (PyLong_Check(v) && (PyTuple_Check(w) || PyFrozenSet_Check(w))) {
+ Py_ssize_t size = PyTuple_Check(w) ? PyTuple_GET_SIZE(w) :
+ PySet_GET_SIZE(w);
+ if (size) {
+ long n = PyLong_AsLong(v);
+ if (n < 0 || n > MAX_COLLECTION_SIZE / size) {
+ return NULL;
+ }
+ if (n && check_complexity(w, MAX_TOTAL_ITEMS / n) < 0) {
+ return NULL;
+ }
+ }
+ }
+ else if (PyLong_Check(v) && (PyUnicode_Check(w) || PyBytes_Check(w))) {
+ Py_ssize_t size = PyUnicode_Check(w) ? PyUnicode_GET_LENGTH(w) :
+ PyBytes_GET_SIZE(w);
+ if (size) {
+ long n = PyLong_AsLong(v);
+ if (n < 0 || n > MAX_STR_SIZE / size) {
+ return NULL;
+ }
+ }
+ }
+ else if (PyLong_Check(w) &&
+ (PyTuple_Check(v) || PyFrozenSet_Check(v) ||
+ PyUnicode_Check(v) || PyBytes_Check(v)))
+ {
+ return safe_multiply(w, v);
+ }
+
+ return PyNumber_Multiply(v, w);
+}
+
+static PyObject *
+safe_power(PyObject *v, PyObject *w)
+{
+ if (PyLong_Check(v) && PyLong_Check(w) && Py_SIZE(v) && Py_SIZE(w) > 0) {
+ size_t vbits = _PyLong_NumBits(v);
+ size_t wbits = PyLong_AsSize_t(w);
+ if (vbits == (size_t)-1 || wbits == (size_t)-1) {
+ return NULL;
+ }
+ if (vbits > MAX_INT_SIZE / wbits) {
+ return NULL;
+ }
+ }
+
+ return PyNumber_Power(v, w, Py_None);
+}
+
+static PyObject *
+safe_lshift(PyObject *v, PyObject *w)
+{
+ if (PyLong_Check(v) && PyLong_Check(w) && Py_SIZE(v) && Py_SIZE(w)) {
+ size_t vbits = _PyLong_NumBits(v);
+ size_t wbits = PyLong_AsSize_t(w);
+ if (vbits == (size_t)-1 || wbits == (size_t)-1) {
+ return NULL;
+ }
+ if (wbits > MAX_INT_SIZE || vbits > MAX_INT_SIZE - wbits) {
+ return NULL;
+ }
+ }
+
+ return PyNumber_Lshift(v, w);
+}
+
+static PyObject *
+safe_mod(PyObject *v, PyObject *w)
+{
+ if (PyUnicode_Check(v) || PyBytes_Check(v)) {
+ return NULL;
+ }
+
+ return PyNumber_Remainder(v, w);
+}
+
/* Replace LOAD_CONST c1, LOAD_CONST c2, BINOP
with LOAD_CONST binop(c1,c2)
The consts table must still be in list form so that the
PyObject *consts, PyObject **objs)
{
PyObject *newconst, *v, *w;
- Py_ssize_t len_consts, size;
+ Py_ssize_t len_consts;
/* Pre-conditions */
assert(PyList_CheckExact(consts));
w = objs[1];
switch (opcode) {
case BINARY_POWER:
- newconst = PyNumber_Power(v, w, Py_None);
+ newconst = safe_power(v, w);
break;
case BINARY_MULTIPLY:
- newconst = PyNumber_Multiply(v, w);
+ newconst = safe_multiply(v, w);
break;
case BINARY_TRUE_DIVIDE:
newconst = PyNumber_TrueDivide(v, w);
newconst = PyNumber_FloorDivide(v, w);
break;
case BINARY_MODULO:
- newconst = PyNumber_Remainder(v, w);
+ newconst = safe_mod(v, w);
break;
case BINARY_ADD:
newconst = PyNumber_Add(v, w);
newconst = PyObject_GetItem(v, w);
break;
case BINARY_LSHIFT:
- newconst = PyNumber_Lshift(v, w);
+ newconst = safe_lshift(v, w);
break;
case BINARY_RSHIFT:
newconst = PyNumber_Rshift(v, w);
}
return -1;
}
- size = PyObject_Size(newconst);
- if (size == -1) {
- if (PyErr_ExceptionMatches(PyExc_KeyboardInterrupt)) {
- return -1;
- }
- PyErr_Clear();
- } else if (size > 20) {
- Py_DECREF(newconst);
- return -1;
- }
/* Append folded constant into consts table */
if (PyList_Append(consts, newconst)) {
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