From e36af2fb51fc170ff6ca2565b6bbe1ef772741d9 Mon Sep 17 00:00:00 2001
From: Alan Coopersmith <alan.coopersmith@oracle.com>
Date: Wed, 22 Jan 2014 21:11:16 -0800
Subject: [PATCH 02/33] dix: integer overflow in ProcPutImage() [CVE-2014-8092
 1/4]

ProcPutImage() calculates a length field from a width, left pad and depth
specified by the client (if the specified format is XYPixmap).

The calculations for the total amount of memory the server needs for the
pixmap can overflow a 32-bit number, causing out-of-bounds memory writes
on 32-bit systems (since the length is stored in a long int variable).

Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Fedora X Ninjas <x@fedoraproject.org>
---
 dix/dispatch.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/dix/dispatch.c b/dix/dispatch.c
index 8dcd9cb..94f262c 100644
--- a/dix/dispatch.c
+++ b/dix/dispatch.c
@@ -1957,6 +1957,9 @@ ProcPutImage(ClientPtr client)
     tmpImage = (char *) &stuff[1];
     lengthProto = length;
 
+    if (lengthProto >= (INT32_MAX / stuff->height))
+        return BadLength;
+
     if ((bytes_to_int32(lengthProto * stuff->height) +
          bytes_to_int32(sizeof(xPutImageReq))) != client->req_len)
         return BadLength;
-- 
1.9.3