Merge tag 'vmwgfx-fixes-4.3-151014' of git://people.freedesktop.org/~thomash/linux...

Pull request of 2015-10-14

* tag 'vmwgfx-fixes-4.3-151014' of git://people.freedesktop.org/~thomash/linux:
  drm/vmwgfx: Fix kernel NULL pointer dereference on older hardware

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
index 64b50409fa0749558844cf561aac983e36197241..03f63c749c02333f412c82184f20def8ce1d8d74 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_surface.c
@@ -657,7 +657,8 @@ static void vmw_user_surface_base_release(struct ttm_base_object **p_base)
        struct vmw_resource *res = &user_srf->srf.res;
 
        *p_base = NULL;
-       ttm_base_object_unref(&user_srf->backup_base);
+       if (user_srf->backup_base)
+               ttm_base_object_unref(&user_srf->backup_base);
        vmw_resource_unreference(&res);
 }