diff options
Diffstat (limited to 'meta/recipes-core/dbus/dbus/CVE-2023-34969.patch')
| -rw-r--r-- | meta/recipes-core/dbus/dbus/CVE-2023-34969.patch | 96 |
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 + |