[Python-checkins] cpython (3.4): prevent overflow in _Unpickler_Read

[benjamin.peterson]

https://hg.python.org/cpython/rev/88d98f6c2d7d
changeset:   98275:88d98f6c2d7d
branch:      3.4
parent:      98270:e494316a9291
user:        Benjamin Peterson <benjamin at python.org>
date:        Sat Sep 26 00:08:34 2015 -0700
summary:
  prevent overflow in _Unpickler_Read

files:
  Misc/NEWS         |  2 ++
  Modules/_pickle.c |  6 ++++++
  2 files changed, 8 insertions(+), 0 deletions(-)


diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -81,6 +81,8 @@
 Library
 -------
 
+- Prevent overflow in _Unpickler_Read.
+
 - Issue #25047: The XML encoding declaration written by Element Tree now
   respects the letter case given by the user. This restores the ability to
   write encoding names in uppercase like "UTF-8", which worked in Python 2.
diff --git a/Modules/_pickle.c b/Modules/_pickle.c
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -1182,6 +1182,12 @@
 {
     Py_ssize_t num_read;
 
+    if (self->next_read_idx > PY_SSIZE_T_MAX - n) {
+        PickleState *st = _Pickle_GetGlobalState();
+        PyErr_SetString(st->UnpicklingError,
+                        "read would overflow (invalid bytecode)");
+        return -1;
+    }
     if (self->next_read_idx + n <= self->input_len) {
         *s = self->input_buffer + self->next_read_idx;
         self->next_read_idx += n;

-- 
Repository URL: https://hg.python.org/cpython