From 74479a99ecf18fdfdafd033b5efd8d785dd12c28 Mon Sep 17 00:00:00 2001
From: Olivier Fourdan <ofourdan@redhat.com>
Date: Fri, 8 Mar 2019 18:19:16 +0100
Subject: [PATCH] glamor: pixmap FBO may not be allocated

If `_glamor_create_tex()` fails to allocate the FBO because of
GL_OUT_OF_MEMORY error, the `pixmap_priv->fbo` is NULL.

However, `glamor_get_pixmap_texture()` doesn't actually check whether
the `pixmap_priv->fbo` is NULL and will segfault with a NULL pointer
dereference trying to access the `pixmap_priv->fbo->tex`.

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Closes: https://gitlab.freedesktop.org/xorg/xserver/issues/647
---
 glamor/glamor.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/glamor/glamor.c b/glamor/glamor.c
index f24cc9fd1..8a9895d95 100644
--- a/glamor/glamor.c
+++ b/glamor/glamor.c
@@ -136,6 +136,9 @@ glamor_get_pixmap_texture(PixmapPtr pixmap)
     if (!pixmap_priv)
         return 0;
 
+    if (!pixmap_priv->fbo)
+        return 0;
+
     if (pixmap_priv->type != GLAMOR_TEXTURE_ONLY)
         return 0;
 
-- 
2.21.0