xserver: Branch 'master'

[Adam Jackson]

 composite/compwindow.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

New commits:
commit efd84bff238f8e12bf652525990d36baada8785b
Author: Peter Harris <pharris at opentext.com>
Date:   Thu Feb 22 18:07:38 2018 -0500

    composite: Fix use-after-free in compReparentWindow
    
    If an implicitly redirected window is unredirected by the reparent
    operation, cw will be a stale pointer.
    
    Signed-off-by: Peter Harris <pharris at opentext.com>
    Reviewed-by: Keith Packard <keithp at keithp.com>

diff --git a/composite/compwindow.c b/composite/compwindow.c
index e74ce661a..54b4e6ac4 100644
--- a/composite/compwindow.c
+++ b/composite/compwindow.c
@@ -432,7 +432,7 @@ compReparentWindow(WindowPtr pWin, WindowPtr pPriorParent)
 {
     ScreenPtr pScreen = pWin->drawable.pScreen;
     CompScreenPtr cs = GetCompScreen(pScreen);
-    CompWindowPtr cw = GetCompWindow(pWin);
+    CompWindowPtr cw;
 
     pScreen->ReparentWindow = cs->ReparentWindow;
     /*
@@ -471,6 +471,7 @@ compReparentWindow(WindowPtr pWin, WindowPtr pPriorParent)
     cs->ReparentWindow = pScreen->ReparentWindow;
     pScreen->ReparentWindow = compReparentWindow;
 
+    cw = GetCompWindow(pWin);
     if (pWin->damagedDescendants || (cw && cw->damaged))
         compMarkAncestors(pWin);