ODROID-U3 xorg-server debian package fork :

[deb_xorg-server.git] / debian / patches / CVE-2014-8xxx / 0020-glx-Be-more-paranoid-about-variable-length-requests-.patch

From 096a5af8e52faafc38ae84dd17bede7ac03a3b83 Mon Sep 17 00:00:00 2001
From: Adam Jackson <ajax@redhat.com>
Date: Mon, 10 Nov 2014 12:13:36 -0500
Subject: [PATCH 20/33] glx: Be more paranoid about variable-length requests
 [CVE-2014-8093 1/6]

If the size computation routine returns -1 we should just reject the
request outright.  Clamping it to zero could give an attacker the
opportunity to also mangle cmdlen in such a way that the subsequent
length check passes, and the request would get executed, thus passing
data we wanted to reject to the renderer.

Reviewed-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Julien Cristau <jcristau@debian.org>
Reviewed-by: Michal Srb <msrb@suse.com>
Reviewed-by: Andy Ritger <aritger@nvidia.com>
Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
---
 glx/glxcmds.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/glx/glxcmds.c
+++ b/glx/glxcmds.c
@@ -2052,7 +2052,7 @@ __glXDisp_Render(__GLXclientState * cl,
             extra = (*entry.varsize) (pc + __GLX_RENDER_HDR_SIZE,
                                       client->swapped);
             if (extra < 0) {
-                extra = 0;
+                return BadLength;
             }
             if (cmdlen != __GLX_PAD(entry.bytes + extra)) {
                 return BadLength;
@@ -2169,7 +2169,7 @@ __glXDisp_RenderLarge(__GLXclientState *
             extra = (*entry.varsize) (pc + __GLX_RENDER_LARGE_HDR_SIZE,
                                       client->swapped);
             if (extra < 0) {
-                extra = 0;
+                return BadLength;
             }
             /* large command's header is 4 bytes longer, so add 4 */
             if (cmdlen != __GLX_PAD(entry.bytes + 4 + extra)) {