@@ 0,0 1,50 @@
+From 9ed6fdd71890c5cc43747f105382d5677e5d37e7 Mon Sep 17 00:00:00 2001
+From: pldubouilh <pldubouilh@gmail.com>
+Date: Fri, 17 Mar 2023 18:23:47 +0100
+Subject: [PATCH] Fix list traversal issue in client_calc_layer
+
+The calls to client_calc_layer_internal can modify stacking_list, which
+can cause us to follow dangling ->next pointers (either by the pointer
+itself already being freed, or it pointing to a freed area). Avoid this
+by copying the list first, the goal is to visit every client in the list
+once so this should be fine.
+---
+ openbox/client.c | 9 +++++++--
+ 1 file changed, 7 insertions(+), 2 deletions(-)
+
+diff --git a/openbox/client.c b/openbox/client.c
+index 7168b2407..b8264587c 100644
+--- a/openbox/client.c
++++ b/openbox/client.c
+@@ -2742,9 +2742,12 @@ static void client_calc_layer_internal(ObClient *self)
+ void client_calc_layer(ObClient *self)
+ {
+     GList *it;
++    /* the client_calc_layer_internal calls below modify stacking_list,
++       so we have to make a copy to iterate over */
++    GList *list = g_list_copy(stacking_list);
+ 
+     /* skip over stuff above fullscreen layer */
+-    for (it = stacking_list; it; it = g_list_next(it))
++    for (it = list; it; it = g_list_next(it))
+         if (window_layer(it->data) <= OB_STACKING_LAYER_FULLSCREEN) break;
+ 
+     /* find the windows in the fullscreen layer, and mark them not-visited */
+@@ -2757,7 +2760,7 @@ void client_calc_layer(ObClient *self)
+     client_calc_layer_internal(self);
+ 
+     /* skip over stuff above fullscreen layer */
+-    for (it = stacking_list; it; it = g_list_next(it))
++    for (it = list; it; it = g_list_next(it))
+         if (window_layer(it->data) <= OB_STACKING_LAYER_FULLSCREEN) break;
+ 
+     /* now recalc any windows in the fullscreen layer which have not
+@@ -2768,6 +2771,8 @@ void client_calc_layer(ObClient *self)
+                  !WINDOW_AS_CLIENT(it->data)->visited)
+             client_calc_layer_internal(it->data);
+     }
++
++    g_list_free(it);
+ }
+ 
+ gboolean client_should_show(ObClient *self)