diff --git a/u_exa-only-draw-valid-trapezoids.patch b/u_exa-only-draw-valid-trapezoids.patch
new file mode 100644
index 0000000..e0b3168
--- /dev/null
+++ b/u_exa-only-draw-valid-trapezoids.patch
@@ -0,0 +1,33 @@
+Author: Maarten Lankhorst <maarten.lankhorst@canonical.com>
+Subject: exa: only draw valid trapezoids
+Patch-Mainline: To be upstreamed
+References: bnc#853846 CVE-2013-6424
+Signed-off-by: Michal Srb <msrb@suse.com>
+
+diff --git a/exa/exa_render.c b/exa/exa_render.c
+index 172e2b5..807eeba 100644
+--- a/exa/exa_render.c
++++ b/exa/exa_render.c
+@@ -1141,7 +1141,8 @@ exaTrapezoids(CARD8 op, PicturePtr pSrc, PicturePtr pDst,
+ 
+         exaPrepareAccess(pPicture->pDrawable, EXA_PREPARE_DEST);
+         for (; ntrap; ntrap--, traps++)
+-            (*ps->RasterizeTrapezoid) (pPicture, traps, -bounds.x1, -bounds.y1);
++            if (xTrapezoidValid(traps))
++                (*ps->RasterizeTrapezoid) (pPicture, traps, -bounds.x1, -bounds.y1);
+         exaFinishAccess(pPicture->pDrawable, EXA_PREPARE_DEST);
+ 
+         xRel = bounds.x1 + xSrc - xDst;
+diff --git a/render/picture.h b/render/picture.h
+index c85353a..fcd6401 100644
+--- a/render/picture.h
++++ b/render/picture.h
+@@ -211,7 +211,7 @@ typedef pixman_fixed_t xFixed;
+ /* whether 't' is a well defined not obviously empty trapezoid */
+ #define xTrapezoidValid(t)  ((t)->left.p1.y != (t)->left.p2.y && \
+ 			     (t)->right.p1.y != (t)->right.p2.y && \
+-			     (int) ((t)->bottom - (t)->top) > 0)
++			     ((t)->bottom > (t)->top))
+ 
+ /*
+  * Standard NTSC luminance conversions:
diff --git a/xorg-x11-server.changes b/xorg-x11-server.changes
index c9b56d1..5ed7365 100644
--- a/xorg-x11-server.changes
+++ b/xorg-x11-server.changes
@@ -1,3 +1,10 @@
+-------------------------------------------------------------------
+Thu Dec 12 14:57:15 UTC 2013 - msrb@suse.com
+
+- u_exa-only-draw-valid-trapezoids.patch
+  * Fix possible x server crash using invalid trapezoids.
+    (bnc#853846 CVE-2013-6424)
+
 -------------------------------------------------------------------
 Thu Dec 12 14:27:20 UTC 2013 - eich@suse.com
 
diff --git a/xorg-x11-server.spec b/xorg-x11-server.spec
index da1b6be..dbd4e49 100644
--- a/xorg-x11-server.spec
+++ b/xorg-x11-server.spec
@@ -128,6 +128,8 @@ Patch102:       u_x86emu-include-order.patch
 Patch103:       u_randr_allow_rrselectinput_for_providerchange_and_resourcechange_events.patch
 Patch104:       u_xorg-server-xdmcp.patch
 Patch105:       ux_xserver_xvfb-randr.patch
+# PATCH-FIX-UPSTREAM u_exa-only-draw-valid-trapezoids.patch bnc#853846 msrb@suse.com -- Fixes possible crash of server using invalid trapezoids. 2013-12-12 patch is waiting in mailing list to be upstreamed.
+Patch106:       u_exa-only-draw-valid-trapezoids.patch
 
 Patch162:       b_cache-xkbcomp-output-for-fast-start-up.patch
 Patch211:       b_0001-Prevent-XSync-Alarms-from-senslessly-calling-CheckTr.patch
@@ -199,6 +201,7 @@ cp %{SOURCE90} .
 %patch103 -p1
 %patch104 -p1
 %patch105 -p1
+%patch106 -p1
 
 ### disabled for now
 #%patch162 -p1