Description of problem:
Application can crash Xorg when the nouveau DRI driver is loaded. This is due to a nullpointer dereference.

Upstream BUG:
https://bugs.freedesktop.org/show_bug.cgi?id=61947

Upstream bug 61947 is fixed in mesa 9.1.2. This bug causes a crash in LabVIEW when dealing with the 3D Math Plot controls. The fix does stop the crash from happening in LabVIEW and restarting X. Upstream bug mention same thing using Chromium.

Version-Release number of selected component (if applicable):
mesa-dri-drivers-9.0-0.8.el6_4.3.x86_64 

mesa-20120924/src/mesa/drivers/dri/nouveau/nouveau_driver.c:
     69                 __DRIdri2LoaderExtension *dri2 = screen->dri2.loader;
     70                 __DRIdrawable *drawable = nctx->dri_context->driDrawablePriv;
     71 
     72                 dri2->flushFrontBuffer(drawable, drawable->loaderPrivate);
     73         }
     74 }

How reproducible:
always

Steps to Reproduce:


Actual results:
crash

Expected results:
no crash

Additional info:
* Upstream patch:
http://cgit.freedesktop.org/mesa/mesa/commit/?id=17f1cb1d99e66227d1e05925ef937643f5c1089a

--- Mesa-9.1/src/mesa/drivers/dri/nouveau/nouveau_driver.c.orig	2013-03-05 22:45:04.381790793 +0000
+++ Mesa-9.1/src/mesa/drivers/dri/nouveau/nouveau_driver.c	2013-03-05 22:47:45.307338871 +0000
@@ -69,7 +69,9 @@
 		__DRIdri2LoaderExtension *dri2 = screen->dri2.loader;
 		__DRIdrawable *drawable = nctx->dri_context->driDrawablePriv;
 
-		dri2->flushFrontBuffer(drawable, drawable->loaderPrivate);
+		if (drawable && drawable->loaderPrivate) {
+			dri2->flushFrontBuffer(drawable, drawable->loaderPrivate);
+		}
 	}
 }

* Bug 862466 - [abrt] firefox-15.0.1-1.fc17: nouveau_flush: Process /usr/lib/firefox/firefox was killed by signal 11 (SIGSEGV)