changeset:   100016:985fc64c60d6
branch:      2.7
parent:      100011:7ec954b9fc54
user:        Benjamin Peterson <benjamin@python.org>
date:        Wed Jan 20 22:23:44 2016 -0800
files:       Misc/NEWS Modules/zipimport.c
description:
prevent buffer overflow in get_data (closes #26171)


diff -r 7ec954b9fc54 -r 985fc64c60d6 Misc/NEWS
--- a/Misc/NEWS	Wed Jan 20 22:06:43 2016 -0800
+++ b/Misc/NEWS	Wed Jan 20 22:23:44 2016 -0800
@@ -36,6 +36,9 @@
   __str__, __trunc__, and __float__ returning instances of subclasses of
   str, long, and float to subclasses of str, long, and float correspondingly.
 
+- Issue #26171: Fix possible integer overflow and heap corruption in
+  zipimporter.get_data().
+
 Library
 -------
 
diff -r 7ec954b9fc54 -r 985fc64c60d6 Modules/zipimport.c
--- a/Modules/zipimport.c	Wed Jan 20 22:06:43 2016 -0800
+++ b/Modules/zipimport.c	Wed Jan 20 22:23:44 2016 -0800
@@ -895,6 +895,11 @@
         PyMarshal_ReadShortFromFile(fp);        /* local header size */
     file_offset += l;           /* Start of file data */
 
+    if (data_size > LONG_MAX - 1) {
+        fclose(fp);
+        PyErr_NoMemory();
+        return NULL;
+    }
     raw_data = PyString_FromStringAndSize((char *)NULL, compress == 0 ?
                                           data_size : data_size + 1);
     if (raw_data == NULL) {