From 1a9f23118787be611b6db51e4eac864c43c702d9 Mon Sep 17 00:00:00 2001
From: Adam Jackson <ajax@redhat.com>
Date: Mon, 10 Nov 2014 12:13:40 -0500
Subject: [PATCH 34/40] glx: Add safe_{add,mul,pad} (v3) [CVE-2014-8093 4/6]
 (v4)

These are paranoid about integer overflow, and will return -1 if their
operation would overflow a (signed) integer or if either argument is
negative.

Note that RenderLarge requests are sized with a uint32_t so in principle
this could be sketchy there, but dix limits bigreqs to 128M so you
shouldn't ever notice, and honestly if you're sending more than 2G of
rendering commands you're already doing something very wrong.

v2: Use INT_MAX for consistency with the rest of the server (jcristau)
v3: Reject negative arguments (anholt)

v4: RHEL5: add limits.h, use inline

v5: backport to nx-libs 3.6.x (Mike DePaulo)

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>
Signed-off-by: Fedora X Ninjas <x@fedoraproject.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 nx-X11/programs/Xserver/GL/glx/glxserver.h | 41 ++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/nx-X11/programs/Xserver/GL/glx/glxserver.h b/nx-X11/programs/Xserver/GL/glx/glxserver.h
index e8449b2..4047574 100644
--- a/nx-X11/programs/Xserver/GL/glx/glxserver.h
+++ b/nx-X11/programs/Xserver/GL/glx/glxserver.h
@@ -54,6 +54,7 @@
 #include "GL/glx_ansic.h"
 
 
+#include <limits.h>
 /*
 ** The X header misc.h defines these math functions.
 */
@@ -223,6 +224,46 @@ extern void glxSwapQueryServerStringReply(ClientPtr client,
 /*
  * Routines for computing the size of variably-sized rendering commands.
  */
+static __inline__ int
+safe_add(int a, int b)
+{
+    if (a < 0 || b < 0)
+        return -1;
+
+    if (INT_MAX - a < b)
+        return -1;
+
+    return a + b;
+}
+
+static __inline__ int
+safe_mul(int a, int b)
+{
+    if (a < 0 || b < 0)
+        return -1;
+
+    if (a == 0 || b == 0)
+        return 0;
+
+    if (a > INT_MAX / b)
+        return -1;
+
+   return a * b;
+}
+
+static __inline__ int
+safe_pad(int a)
+{
+    int ret;
+
+    if (a < 0)
+        return -1;
+
+    if ((ret = safe_add(a, 3)) < 0)
+        return -1;
+
+    return ret & (GLuint)~3;
+}
 
 extern int __glXTypeSize(GLenum enm);
 extern int __glXImageSize(GLenum format, GLenum type,
-- 
2.1.4