From 45b76b121a6f7fd01742b78f9c44a48a3caffbf0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20M=C3=BCllner?= <fmuellner@gnome.org>
Date: Fri, 10 Jan 2014 06:26:57 -0500
Subject: [PATCH 1/2] window-actor: Guard against %NULL frame mask

Creating a new cogl texture may fail, in which case the intent to
free it will crash. While something is clearly wrong (insanely
large window, oom, ...), crashing the WM is harsh and we should
try to avoid it if at all possible, so carry on.

https://bugzilla.gnome.org/show_bug.cgi?id=722266
---
 src/compositor/meta-window-actor.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/compositor/meta-window-actor.c b/src/compositor/meta-window-actor.c
index 42d1257..055b413 100644
--- a/src/compositor/meta-window-actor.c
+++ b/src/compositor/meta-window-actor.c
@@ -2181,7 +2181,8 @@ build_and_scan_frame_mask (MetaWindowActor       *self,
 
   meta_shaped_texture_set_mask_texture (META_SHAPED_TEXTURE (priv->actor),
                                         mask_texture);
-  cogl_object_unref (mask_texture);
+  if (mask_texture)
+    cogl_object_unref (mask_texture);
 
   g_free (mask_data);
 }
-- 
1.9.0


From bd6fa34598b774de36c4c65d2cfa577c24f18722 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20M=C3=BCllner?= <fmuellner@gnome.org>
Date: Wed, 12 Mar 2014 02:04:13 +0100
Subject: [PATCH 2/2] constraints: Enforce X11 size limits

X11 limits windows to a maximum of 32767x32767, enforce that restriction
to keep insanely huge windows from crashing the WM.
---
 src/core/constraints.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/src/core/constraints.c b/src/core/constraints.c
index 606baea..2a510e0 100644
--- a/src/core/constraints.c
+++ b/src/core/constraints.c
@@ -104,6 +104,7 @@ typedef enum
   PRIORITY_SIZE_HINTS_LIMITS = 3,
   PRIORITY_TITLEBAR_VISIBLE = 4,
   PRIORITY_PARTIALLY_VISIBLE_ON_WORKAREA = 4,
+  PRIORITY_XLIMITS = 4,
   PRIORITY_MAXIMUM = 4 /* Dummy value used for loop end = max(all priorities) */
 } ConstraintPriority;
 
@@ -192,6 +193,10 @@ static gboolean constrain_partially_onscreen (MetaWindow         *window,
                                               ConstraintInfo     *info,
                                               ConstraintPriority  priority,
                                               gboolean            check_only);
+static gboolean constrain_xlimits            (MetaWindow         *window,
+                                              ConstraintInfo     *info,
+                                              ConstraintPriority  priority,
+                                              gboolean            check_only);
 
 static void setup_constraint_info        (ConstraintInfo      *info,
                                           MetaWindow          *window,
@@ -236,6 +241,7 @@ static const Constraint all_constraints[] = {
   {constrain_fully_onscreen,     "constrain_fully_onscreen"},
   {constrain_titlebar_visible,   "constrain_titlebar_visible"},
   {constrain_partially_onscreen, "constrain_partially_onscreen"},
+  {constrain_xlimits,            "constrain_xlimits"},
   {NULL,                         NULL}
 };
 
@@ -1518,3 +1524,36 @@ constrain_partially_onscreen (MetaWindow         *window,
 
   return retval;
 }
+
+
+#define MAX_WINDOW_SIZE 32767
+
+static gboolean
+constrain_xlimits (MetaWindow         *window,
+                   ConstraintInfo     *info,
+                   ConstraintPriority  priority,
+                   gboolean            check_only)
+{
+  int max_w, max_h;
+  gboolean constraint_already_satisfied;
+
+  if (priority > PRIORITY_XLIMITS)
+    return TRUE;
+
+  max_w = MAX_WINDOW_SIZE;
+  if (window->frame)
+    max_w -= (info->borders->total.left + info->borders->total.right);
+
+  max_h = MAX_WINDOW_SIZE;
+  if (window->frame)
+    max_h -= (info->borders->total.top + info->borders->total.bottom);
+
+  constraint_already_satisfied = info->current.width < max_w && info->current.height < max_h;
+  if (check_only || constraint_already_satisfied)
+    return constraint_already_satisfied;
+
+  info->current.width = MIN (info->current.width, max_w);
+  info->current.height = MIN (info->current.height, max_h);
+
+  return TRUE;
+}
-- 
1.9.0