[Qemu-devel] Patch: Precautionary glBindTexture in surface_gl_update_texture

[Hou Qiming]

>From 48d1f092a7960d711fb2c77ab8d3f9d0a0ca0d5c Mon Sep 17 00:00:00 2001
From: HQM <address@hidden>
Date: Mon, 6 May 2019 15:37:59 +0800
Subject: [PATCH] Precautionary glBindTexture and surface->texture validation
 in surface_gl_update_texture

In a GVT-g setup with dmabuf and GTK GUI, the current 2D texture at
surface_gl_update_texture is not necessarily
surface->texture. Adding a glBindTexture fixes related crashes and
artifacts, and is generally more secure.

Signed-off-by: HQM <address@hidden>
---
 ui/console-gl.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/ui/console-gl.c b/ui/console-gl.c
index a56e1cd..c1cb3bd 100644
--- a/ui/console-gl.c
+++ b/ui/console-gl.c
@@ -92,13 +92,17 @@ void surface_gl_update_texture(QemuGLShader *gls,

     assert(gls);

-    glPixelStorei(GL_UNPACK_ROW_LENGTH_EXT,
-                  surface_stride(surface) /
surface_bytes_per_pixel(surface));
-    glTexSubImage2D(GL_TEXTURE_2D, 0,
-                    x, y, w, h,
-                    surface->glformat, surface->gltype,
-                    data + surface_stride(surface) * y
-                    + surface_bytes_per_pixel(surface) * x);
+    if (surface->texture) {
+        glBindTexture(GL_TEXTURE_2D, surface->texture);
+        glPixelStorei(GL_UNPACK_ROW_LENGTH_EXT,
+                      surface_stride(surface)
+                      / surface_bytes_per_pixel(surface));
+        glTexSubImage2D(GL_TEXTURE_2D, 0,
+                        x, y, w, h,
+                        surface->glformat, surface->gltype,
+                        data + surface_stride(surface) * y
+                        + surface_bytes_per_pixel(surface) * x);
+    }
 }

 void surface_gl_render_texture(QemuGLShader *gls,
-- 
2.17.1