glib2.0/debian/patches/CVE-2024-34397-12.patch

68 lines
3.0 KiB
Diff

From: Simon McVittie <smcv@collabora.com>
Date: Thu, 14 Mar 2024 20:42:41 +0000
Subject: [PATCH 12/16] gdbusconnection: Don't deliver signals if the sender
doesn't match
Otherwise a malicious connection on a shared bus, especially the system
bus, could trick GDBus clients into processing signals sent by the
malicious connection as though they had come from the real owner of a
well-known service name.
Resolves: https://gitlab.gnome.org/GNOME/glib/-/issues/3268
Signed-off-by: Simon McVittie <smcv@collabora.com>
---
gio/gdbusconnection.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/gio/gdbusconnection.c b/gio/gdbusconnection.c
index a0ebe37..e707716 100644
--- a/gio/gdbusconnection.c
+++ b/gio/gdbusconnection.c
@@ -4299,6 +4299,46 @@ schedule_callbacks (GDBusConnection *connection,
if (signal_data->object_path != NULL && g_strcmp0 (signal_data->object_path, path) != 0)
continue;
+ if (signal_data->shared_name_watcher != NULL)
+ {
+ /* We want signals from a specified well-known name, which means
+ * the signal's sender needs to be the unique name that currently
+ * owns that well-known name, and we will have found this
+ * SignalData in
+ * connection->map_sender_unique_name_to_signal_data_array[""]. */
+ const WatchedName *watched_name;
+ const char *current_owner;
+
+ g_assert (signal_data->sender != NULL);
+ /* Invariant: We never need to watch for the owner of a unique
+ * name, or for the owner of DBUS_SERVICE_DBUS, either of which
+ * is always its own owner */
+ g_assert (!g_dbus_is_unique_name (signal_data->sender));
+ g_assert (g_strcmp0 (signal_data->sender, DBUS_SERVICE_DBUS) != 0);
+
+ watched_name = signal_data->shared_name_watcher->watched_name;
+ g_assert (watched_name != NULL);
+ current_owner = watched_name->owner;
+
+ /* Skip the signal if the actual sender is not known to own
+ * the required name */
+ if (current_owner == NULL || g_strcmp0 (current_owner, sender) != 0)
+ continue;
+ }
+ else if (signal_data->sender != NULL)
+ {
+ /* We want signals from a unique name or o.fd.DBus... */
+ g_assert (g_dbus_is_unique_name (signal_data->sender)
+ || g_str_equal (signal_data->sender, DBUS_SERVICE_DBUS));
+
+ /* ... which means we must have found this SignalData in
+ * connection->map_sender_unique_name_to_signal_data_array[signal_data->sender],
+ * therefore we would only have found it if the signal's
+ * actual sender matches the required signal_data->sender */
+ g_assert (g_strcmp0 (signal_data->sender, sender) == 0);
+ }
+ /* else the sender is unspecified and we will accept anything */
+
if (signal_data->arg0 != NULL)
{
if (signal_data->flags & G_DBUS_SIGNAL_FLAGS_MATCH_ARG0_NAMESPACE)