[Mesa-stable] [PATCH] egl: avoid eglCreatePlatform*Surface{EXT, } crash with invalid dpy

[Emil Velikov]

From: Emil Velikov <emil.velikov at collabora.com>

If we have an invalid display fed into the functions, the display lookup
will return NULL. Thus as we attempt to get the platform type, we'll
deref. it leading to a crash.

Keep in mind that this will not happen if Mesa is built without X11 or
when the legacy eglCreate*Surface codepaths are used.

An similar check was added with earlier commit 5e97b8f5ce9 ("egl: Fix
crashes in eglCreate*Surface), although it was only applicable when the
surfaceless platform is built.

Cc: mesa-stable at lists.freedesktop.org
Cc: Tapani Pälli <tapani.palli at intel.com>
Cc: Chad Versace <chadversary at chromium.org>
Signed-off-by: Emil Velikov <emil.velikov at collabora.com>
---
 src/egl/main/eglapi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/egl/main/eglapi.c b/src/egl/main/eglapi.c
index c5e3955c48c..8146009da4f 100644
--- a/src/egl/main/eglapi.c
+++ b/src/egl/main/eglapi.c
@@ -923,7 +923,7 @@ static void *
 _fixupNativeWindow(_EGLDisplay *disp, void *native_window)
 {
 #ifdef HAVE_X11_PLATFORM
-   if (disp->Platform == _EGL_PLATFORM_X11 && native_window != NULL) {
+   if (disp && disp->Platform == _EGL_PLATFORM_X11 && native_window != NULL) {
       /* The `native_window` parameter for the X11 platform differs between
        * eglCreateWindowSurface() and eglCreatePlatformPixmapSurfaceEXT(). In
        * eglCreateWindowSurface(), the type of `native_window` is an Xlib
@@ -985,7 +985,7 @@ _fixupNativePixmap(_EGLDisplay *disp, void *native_pixmap)
        * `Pixmap*`.  Convert `Pixmap*` to `Pixmap` because that's what
        * dri2_x11_create_pixmap_surface() expects.
        */
-   if (disp->Platform == _EGL_PLATFORM_X11 && native_pixmap != NULL)
+   if (disp && disp->Platform == _EGL_PLATFORM_X11 && native_pixmap != NULL)
       return (void *)(* (Pixmap*) native_pixmap);
 #endif
    return native_pixmap;
-- 
2.14.0