| From c86aea01a06ad4d6c428137e9cfe2f74b1ae7f01 Mon Sep 17 00:00:00 2001 |
| From: Jan Rybar <jrybar@redhat.com> |
| Date: Mon, 21 Feb 2022 08:29:05 +0000 |
| Subject: [PATCH 2/3] CVE-2021-4115 (GHSL-2021-077) fix |
| |
| Signed-off-by: Mikko Rapeli <mikko.rapeli@bmw.de> |
| |
| --- |
| src/polkit/polkitsystembusname.c | 38 ++++++++++++++++++++++++++++---- |
| 1 file changed, 34 insertions(+), 4 deletions(-) |
| |
| CVE: CVE-2021-4115 |
| Upstream-Status: Backport [41cb093f554da8772362654a128a84dd8a5542a7] |
| |
| diff --git a/src/polkit/polkitsystembusname.c b/src/polkit/polkitsystembusname.c |
| index 8ed1363..2fbf5f1 100644 |
| --- a/src/polkit/polkitsystembusname.c |
| +++ b/src/polkit/polkitsystembusname.c |
| @@ -62,6 +62,10 @@ enum |
| PROP_NAME, |
| }; |
| |
| + |
| +guint8 dbus_call_respond_fails; // has to be global because of callback |
| + |
| + |
| static void subject_iface_init (PolkitSubjectIface *subject_iface); |
| |
| G_DEFINE_TYPE_WITH_CODE (PolkitSystemBusName, polkit_system_bus_name, G_TYPE_OBJECT, |
| @@ -364,6 +368,7 @@ on_retrieved_unix_uid_pid (GObject *src, |
| if (!v) |
| { |
| data->caught_error = TRUE; |
| + dbus_call_respond_fails += 1; |
| } |
| else |
| { |
| @@ -405,6 +410,8 @@ polkit_system_bus_name_get_creds_sync (PolkitSystemBusName *system_bus |
| tmp_context = g_main_context_new (); |
| g_main_context_push_thread_default (tmp_context); |
| |
| + dbus_call_respond_fails = 0; |
| + |
| /* Do two async calls as it's basically as fast as one sync call. |
| */ |
| g_dbus_connection_call (connection, |
| @@ -432,11 +439,34 @@ polkit_system_bus_name_get_creds_sync (PolkitSystemBusName *system_bus |
| on_retrieved_unix_uid_pid, |
| &data); |
| |
| - while (!((data.retrieved_uid && data.retrieved_pid) || data.caught_error)) |
| - g_main_context_iteration (tmp_context, TRUE); |
| + while (TRUE) |
| + { |
| + /* If one dbus call returns error, we must wait until the other call |
| + * calls _call_finish(), otherwise fd leak is possible. |
| + * Resolves: GHSL-2021-077 |
| + */ |
| |
| - if (data.caught_error) |
| - goto out; |
| + if ( (dbus_call_respond_fails > 1) ) |
| + { |
| + // we got two faults, we can leave |
| + goto out; |
| + } |
| + |
| + if ((data.caught_error && (data.retrieved_pid || data.retrieved_uid))) |
| + { |
| + // we got one fault and the other call finally finished, we can leave |
| + goto out; |
| + } |
| + |
| + if ( !(data.retrieved_uid && data.retrieved_pid) ) |
| + { |
| + g_main_context_iteration (tmp_context, TRUE); |
| + } |
| + else |
| + { |
| + break; |
| + } |
| + } |
| |
| if (out_uid) |
| *out_uid = data.uid; |
| -- |
| 2.20.1 |
| |