[Python-checkins] cpython (2.7): detect overflow in combinations (closes #23366)

Mon Feb 2 03:05:12 CET 2015

https://hg.python.org/cpython/rev/fe203370c049
changeset: 94451:fe203370c049
branch: 2.7
parent: 94446:1cc37c52fed4
user: Benjamin Peterson <benjamin at python.org>
date: Sun Feb 01 20:59:00 2015 -0500
summary:
 detect overflow in combinations (closes #23366)
files:
 Lib/test/test_itertools.py | 5 +++++
 Misc/NEWS | 2 ++
 Modules/itertoolsmodule.c | 4 ++++
 3 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -137,6 +137,11 @@
 self.assertEqual(result, list(combinations2(values, r))) # matches second pure python version
 self.assertEqual(result, list(combinations3(values, r))) # matches second pure python version
 
+ @test_support.bigaddrspacetest
+ def test_combinations_overflow(self):
+ with self.assertRaises(OverflowError):
+ combinations("AA", 2**29)
+
 @test_support.impl_detail("tuple reuse is specific to CPython")
 def test_combinations_tuple_reuse(self):
 self.assertEqual(len(set(map(id, combinations('abcde', 3)))), 1)
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -18,6 +18,8 @@
 Library
 -------
 
+- Issue #23366: Fixed possible integer overflow in itertools.combinations.
+
 - Issue #23191: fnmatch functions that use caching are now threadsafe.
 
 - Issue #18518: timeit now rejects statements which can't be compiled outside
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -2093,6 +2093,10 @@
 goto error;
 }
 
+ if (r > PY_SSIZE_T_MAX/sizeof(Py_ssize_t)) {
+ PyErr_SetString(PyExc_OverflowError, "r is too big");
+ goto error;
+ }
 indices = PyMem_Malloc(r * sizeof(Py_ssize_t));
 if (indices == NULL) {
 PyErr_NoMemory();
-- 
Repository URL: https://hg.python.org/cpython
