Merge branch '861-dbus-menu-model-robustness' into 'main'

gmenumodel: disallow exporting large menus on the bus

Closes #861

See merge request GNOME/glib!3133
This commit is contained in:
Philip Withnall 2022-12-14 16:18:07 +00:00
commit 8a60c22bb4
5 changed files with 198 additions and 4 deletions

View File

@ -4328,6 +4328,7 @@ g_power_profile_level_get_type
<SECTION>
<FILE>gmenuexporter</FILE>
G_MENU_EXPORTER_MAX_SECTION_SIZE
g_dbus_connection_export_menu_model
g_dbus_connection_unexport_menu_model
</SECTION>

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@ -23,6 +23,7 @@
#include "gdbusmenumodel.h"
#include "gmenuexporter.h"
#include "gmenumodel.h"
/* Prelude {{{1 */
@ -580,6 +581,8 @@ g_dbus_menu_group_deactivate (GDBusMenuGroup *group)
}
}
/* @menu_id, @position, @removed and @added are all untrusted since they can
* come from an external process. */
static void
g_dbus_menu_group_changed (GDBusMenuGroup *group,
guint menu_id,
@ -593,6 +596,20 @@ g_dbus_menu_group_changed (GDBusMenuGroup *group,
GSequence *items;
GVariant *item;
gint n_added;
gint n_items;
/* Caller has to check this. */
g_assert (g_variant_is_of_type (added, G_VARIANT_TYPE ("aa{sv}")));
n_added = g_variant_n_children (added);
if (position < 0 || position >= G_MENU_EXPORTER_MAX_SECTION_SIZE ||
removed < 0 || removed >= G_MENU_EXPORTER_MAX_SECTION_SIZE ||
n_added >= G_MENU_EXPORTER_MAX_SECTION_SIZE)
{
g_warning ("invalid arguments");
return;
}
/* We could have signals coming to us when we're not active (due to
* some other process having subscribed to this group) or when we're
@ -611,9 +628,17 @@ g_dbus_menu_group_changed (GDBusMenuGroup *group,
g_hash_table_insert (group->menus, GINT_TO_POINTER (menu_id), items);
}
point = g_sequence_get_iter_at_pos (items, position + removed);
/* Dont need to worry about overflow due to the low value of
* %G_MENU_EXPORTER_MAX_SECTION_SIZE. */
n_items = g_sequence_get_length (items);
if (position + removed > n_items ||
n_items - removed + n_added > G_MENU_EXPORTER_MAX_SECTION_SIZE)
{
g_warning ("invalid arguments");
return;
}
g_return_if_fail (point != NULL);
point = g_sequence_get_iter_at_pos (items, position + removed);
if (removed)
{
@ -623,7 +648,7 @@ g_dbus_menu_group_changed (GDBusMenuGroup *group,
g_sequence_remove_range (start, point);
}
n_added = g_variant_iter_init (&iter, added);
g_variant_iter_init (&iter, added);
while (g_variant_iter_loop (&iter, "@a{sv}", &item))
g_sequence_insert_before (point, g_dbus_menu_group_create_item (item));

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@ -252,10 +252,17 @@ g_menu_exporter_menu_items_changed (GMenuModel *model,
GMenuExporterMenu *menu = user_data;
GSequenceIter *point;
gint i;
gint n_items;
g_assert (menu->model == model);
g_assert (menu->item_links != NULL);
g_assert (position + removed <= g_sequence_get_length (menu->item_links));
n_items = g_sequence_get_length (menu->item_links);
g_assert (position >= 0 && position < G_MENU_EXPORTER_MAX_SECTION_SIZE);
g_assert (removed >= 0 && removed < G_MENU_EXPORTER_MAX_SECTION_SIZE);
g_assert (added < G_MENU_EXPORTER_MAX_SECTION_SIZE);
g_assert (position + removed <= n_items);
g_assert (n_items - removed + added < G_MENU_EXPORTER_MAX_SECTION_SIZE);
point = g_sequence_get_iter_at_pos (menu->item_links, position + removed);
g_sequence_remove_range (g_sequence_get_iter_at_pos (menu->item_links, position), point);
@ -770,6 +777,10 @@ g_menu_exporter_method_call (GDBusConnection *connection,
* constraint is violated, the export will fail and 0 will be
* returned (with @error set accordingly).
*
* Exporting menus with sections containing more than
* %G_MENU_EXPORTER_MAX_SECTION_SIZE items is not supported and results in
* undefined behavior.
*
* You can unexport the menu model using
* g_dbus_connection_unexport_menu_model() with the return value of
* this function.

View File

@ -27,6 +27,19 @@
G_BEGIN_DECLS
/**
* G_MENU_EXPORTER_MAX_SECTION_SIZE:
*
* The maximum number of entries in a menu section supported by
* g_dbus_connection_export_menu_model().
*
* The exact value of the limit may change in future GLib versions.
*
* Since: 2.76
*/
#define G_MENU_EXPORTER_MAX_SECTION_SIZE 1000 \
GIO_AVAILABLE_MACRO_IN_2_76
GIO_AVAILABLE_IN_2_32
guint g_dbus_connection_export_menu_model (GDBusConnection *connection,
const gchar *object_path,

View File

@ -1500,6 +1500,149 @@ test_menuitem (void)
g_object_unref (submenu);
}
static GDBusInterfaceInfo *
org_gtk_Menus_get_interface (void)
{
static GDBusInterfaceInfo *interface_info;
if (interface_info == NULL)
{
GError *error = NULL;
GDBusNodeInfo *info;
info = g_dbus_node_info_new_for_xml ("<node>"
" <interface name='org.gtk.Menus'>"
" <method name='Start'>"
" <arg type='au' name='groups' direction='in'/>"
" <arg type='a(uuaa{sv})' name='content' direction='out'/>"
" </method>"
" <method name='End'>"
" <arg type='au' name='groups' direction='in'/>"
" </method>"
" <signal name='Changed'>"
" arg type='a(uuuuaa{sv})' name='changes'/>"
" </signal>"
" </interface>"
"</node>", &error);
if (info == NULL)
g_error ("%s\n", error->message);
interface_info = g_dbus_node_info_lookup_interface (info, "org.gtk.Menus");
g_assert (interface_info != NULL);
g_dbus_interface_info_ref (interface_info);
g_dbus_node_info_unref (info);
}
return interface_info;
}
static void
g_menu_exporter_method_call (GDBusConnection *connection,
const gchar *sender,
const gchar *object_path,
const gchar *interface_name,
const gchar *method_name,
GVariant *parameters,
GDBusMethodInvocation *invocation,
gpointer user_data)
{
const struct {
guint position;
guint removed;
} data[] = {
{ -2, 4 },
{ 0, 3 },
{ 4, 1 }
};
gsize i;
GError *error = NULL;
g_dbus_method_invocation_return_value (invocation, g_variant_new_parsed ("@(a(uuaa{sv})) ([(0, 0, [{ 'label': <'test'> }])],)"));
/* invalid signatures */
g_dbus_connection_emit_signal (connection, sender, "/", "org.gtk.Menus", "Changed",
g_variant_new_parsed ("([(1, 2, 3)],)"), &error);
g_assert_no_error (error);
/* add an item at an invalid position */
g_test_expect_message (G_LOG_DOMAIN, G_LOG_LEVEL_WARNING, "*invalid*");
g_dbus_connection_emit_signal (connection, sender, "/", "org.gtk.Menus", "Changed",
g_variant_new_parsed ("@(a(uuuuaa{sv})) ([(%u, %u, %u, %u, [{ 'label': <'test'> }])],)", 0, 0, 2, 0),
&error);
g_assert_no_error (error);
for (i = 0; i < G_N_ELEMENTS (data); i++)
{
GVariant *params;
g_test_expect_message (G_LOG_DOMAIN, G_LOG_LEVEL_WARNING, "*invalid*");
params = g_variant_new_parsed ("@(a(uuuuaa{sv})) ([(%u, %u, %u, %u, [])],)", 0, 0, data[i].position, data[i].removed);
g_dbus_connection_emit_signal (connection, sender, "/", "org.gtk.Menus", "Changed", params, &error);
g_assert_no_error (error);
}
}
static void
menu_changed (GMenuModel *menu,
gint position,
gint removed,
gint added,
gpointer user_data)
{
unsigned int *counter = user_data;
*counter += 1;
}
static void
test_input_validation (void)
{
const GDBusInterfaceVTable vtable = {
g_menu_exporter_method_call, NULL, NULL, { NULL, }
};
GError *error = NULL;
GDBusConnection *bus;
GDBusMenuModel *proxy;
guint id;
const gchar *bus_name;
GMainLoop *loop;
unsigned int n_signal_emissions = 0;
gulong signal_id;
g_test_bug ("https://gitlab.gnome.org/GNOME/glib/-/issues/861");
bus = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, &error);
g_assert_no_error (error);
id = g_dbus_connection_register_object (bus, "/", org_gtk_Menus_get_interface (),
&vtable, NULL, NULL, &error);
g_assert_no_error (error);
bus_name = g_dbus_connection_get_unique_name (bus);
proxy = g_dbus_menu_model_get (bus, bus_name, "/");
signal_id = g_signal_connect (proxy, "items-changed", G_CALLBACK (menu_changed), &n_signal_emissions);
/* get over laziness */
g_menu_model_get_n_items (G_MENU_MODEL (proxy));
loop = g_main_loop_new (NULL, FALSE);
g_timeout_add (100, stop_loop, loop);
g_main_loop_run (loop);
/* "items-changed" should only be emitted for the initial contents of
* the menu. Subsequent calls are all invalid.
*/
g_assert_cmpuint (n_signal_emissions, ==, 1);
g_test_assert_expected_messages ();
g_main_loop_unref (loop);
g_dbus_connection_unregister_object (bus, id);
g_signal_handler_disconnect (proxy, signal_id);
g_object_unref (proxy);
g_object_unref (bus);
}
/* Epilogue {{{1 */
int
main (int argc, char **argv)
@ -1523,6 +1666,7 @@ main (int argc, char **argv)
g_test_add_func ("/gmenu/mutable", test_mutable);
g_test_add_func ("/gmenu/convenience", test_convenience);
g_test_add_func ("/gmenu/menuitem", test_menuitem);
g_test_add_func ("/gmenu/input-validation", test_input_validation);
ret = g_test_run ();