changeset:   103779:5ae8756a1ae0
branch:      3.3
parent:      102713:8e3b9bf917a7
user:        Berker Peksag <berker.peksag@gmail.com>
date:        Wed Sep 14 08:37:28 2016 +0300
files:       Misc/NEWS Modules/zipimport.c
description:
Issue #26171: Prevent buffer overflow in get_data

Backport of 01ddd608b85c.


diff -r 8e3b9bf917a7 -r 5ae8756a1ae0 Misc/NEWS
--- a/Misc/NEWS	Tue Aug 16 23:35:35 2016 -0700
+++ b/Misc/NEWS	Wed Sep 14 08:37:28 2016 +0300
@@ -10,6 +10,9 @@
 Core and Builtins
 -----------------
 
+- Issue #26171: Fix possible integer overflow and heap corruption in
+  zipimporter.get_data().
+
 - Issue #25709: Fixed problem with in-place string concatenation and utf-8 cache.
 
 - Issue #24407: Fix crash when dict is mutated while being updated.
diff -r 8e3b9bf917a7 -r 5ae8756a1ae0 Modules/zipimport.c
--- a/Modules/zipimport.c	Tue Aug 16 23:35:35 2016 -0700
+++ b/Modules/zipimport.c	Wed Sep 14 08:37:28 2016 +0300
@@ -1089,6 +1089,11 @@
         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;
+    }
     bytes_size = compress == 0 ? data_size : data_size + 1;
     if (bytes_size == 0)
         bytes_size++;