1 files changed, 96 insertions, 0 deletions

diff --git a/meta/recipes-core/dbus/dbus/CVE-2023-34969.patch b/meta/recipes-core/dbus/dbus/CVE-2023-34969.patch
new file mode 100644
index 0000000000..8f29185cf6
--- /dev/null
+++ b/meta/recipes-core/dbus/dbus/CVE-2023-34969.patch
@@ -0,0 +1,96 @@
+From 37a4dc5835731a1f7a81f1b67c45b8dfb556dd1c Mon Sep 17 00:00:00 2001
+From: hongjinghao <q1204531485@163.com>
+Date: Mon, 5 Jun 2023 18:17:06 +0100
+Subject: [PATCH] bus: Assign a serial number for messages from the driver
+
+Normally, it's enough to rely on a message being given a serial number
+by the DBusConnection just before it is actually sent. However, in the
+rare case where the policy blocks the driver from sending a message
+(due to a deny rule or the outgoing message quota being full), we need
+to get a valid serial number sooner, so that we can copy it into the
+DBUS_HEADER_FIELD_REPLY_SERIAL field (which is mandatory) in the error
+message sent to monitors. Otherwise, the dbus-daemon will crash with
+an assertion failure if at least one Monitoring client is attached,
+because zero is not a valid serial number to copy.
+
+This fixes a denial-of-service vulnerability: if a privileged user is
+monitoring the well-known system bus using a Monitoring client like
+dbus-monitor or `busctl monitor`, then an unprivileged user can cause
+denial-of-service by triggering this crash. A mitigation for this
+vulnerability is to avoid attaching Monitoring clients to the system
+bus when they are not needed. If there are no Monitoring clients, then
+the vulnerable code is not reached.
+
+Co-authored-by: Simon McVittie <smcv@collabora.com>
+Resolves: dbus/dbus#457
+(cherry picked from commit b159849e031000d1dbc1ab876b5fc78a3ce9b534)
+---
+ bus/connection.c                | 15 +++++++++++++++
+ dbus/dbus-connection-internal.h |  2 ++
+ dbus/dbus-connection.c          | 11 ++++++++++-
+ 3 files changed, 27 insertions(+), 1 deletion(-)
+
+diff --git a/bus/connection.c b/bus/connection.c
+index b3583433..215f0230 100644
+--- a/bus/connection.c
++++ b/bus/connection.c
+@@ -2350,6 +2350,21 @@ bus_transaction_send_from_driver (BusTransaction *transaction,
+   if (!dbus_message_set_sender (message, DBUS_SERVICE_DBUS))
+     return FALSE;
+ 
++  /* Make sure the message has a non-zero serial number, otherwise
++   * bus_transaction_capture_error_reply() will not be able to mock up
++   * a corresponding reply for it. Normally this would be delayed until
++   * the first time we actually send the message out from a
++   * connection, when the transaction is committed, but that's too late
++   * in this case.
++   */
++  if (dbus_message_get_serial (message) == 0)
++    {
++      dbus_uint32_t next_serial;
++
++      next_serial = _dbus_connection_get_next_client_serial (connection);
++      dbus_message_set_serial (message, next_serial);
++    }
++
+   if (bus_connection_is_active (connection))
+     {
+       if (!dbus_message_set_destination (message,
+diff --git a/dbus/dbus-connection-internal.h b/dbus/dbus-connection-internal.h
+index 48357321..ba79b192 100644
+--- a/dbus/dbus-connection-internal.h
++++ b/dbus/dbus-connection-internal.h
+@@ -54,6 +54,8 @@ DBUS_PRIVATE_EXPORT
+ DBusConnection *  _dbus_connection_ref_unlocked                (DBusConnection     *connection);
+ DBUS_PRIVATE_EXPORT
+ void              _dbus_connection_unref_unlocked              (DBusConnection     *connection);
++DBUS_PRIVATE_EXPORT
++dbus_uint32_t     _dbus_connection_get_next_client_serial      (DBusConnection *connection);
+ void              _dbus_connection_queue_received_message_link (DBusConnection     *connection,
+                                                                 DBusList           *link);
+ dbus_bool_t       _dbus_connection_has_messages_to_send_unlocked (DBusConnection     *connection);
+diff --git a/dbus/dbus-connection.c b/dbus/dbus-connection.c
+index c525b6dc..09cef278 100644
+--- a/dbus/dbus-connection.c
++++ b/dbus/dbus-connection.c
+@@ -1456,7 +1456,16 @@ _dbus_connection_unref_unlocked (DBusConnection *connection)
+     _dbus_connection_last_unref (connection);
+ }
+ 
+-static dbus_uint32_t
++/**
++ * Allocate and return the next non-zero serial number for outgoing messages.
++ *
++ * This method is only valid to call from single-threaded code, such as
++ * the dbus-daemon, or with the connection lock held.
++ *
++ * @param connection the connection
++ * @returns A suitable serial number for the next message to be sent on the connection.
++ */
++dbus_uint32_t
+ _dbus_connection_get_next_client_serial (DBusConnection *connection)
+ {
+   dbus_uint32_t serial;
+-- 
+2.25.1
+