From bf44d9965b5cc0f0ee31ba2579783d8194fff756 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 2 Oct 2012 12:22:51 +0100
Subject: [PATCH] sna: Prevent sna_damage_contains_box__no_reduce() from a NULL
 deref

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
 src/sna/sna_accel.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/sna/sna_accel.c b/src/sna/sna_accel.c
index b5e6730f..62bf1d46 100644
--- a/src/sna/sna_accel.c
+++ b/src/sna/sna_accel.c
@@ -2855,7 +2855,8 @@ use_cpu_bo:
 		sna_damage_destroy(&priv->gpu_damage);
 		*damage = NULL;
 	} else {
-		if (sna_damage_contains_box__no_reduce(priv->cpu_damage,
+		if (priv->cpu_damage &&
+		    sna_damage_contains_box__no_reduce(priv->cpu_damage,
 						       &region.extents))
 			*damage = NULL;
 		else