| Andrew Geissler | 9aee500 | 2022-03-30 16:27:02 +0000 | [diff] [blame^] | 1 | From c86aea01a06ad4d6c428137e9cfe2f74b1ae7f01 Mon Sep 17 00:00:00 2001 |
| 2 | From: Jan Rybar <jrybar@redhat.com> |
| 3 | Date: Mon, 21 Feb 2022 08:29:05 +0000 |
| 4 | Subject: [PATCH 2/3] CVE-2021-4115 (GHSL-2021-077) fix |
| 5 | |
| 6 | Signed-off-by: Mikko Rapeli <mikko.rapeli@bmw.de> |
| 7 | |
| 8 | --- |
| 9 | src/polkit/polkitsystembusname.c | 38 ++++++++++++++++++++++++++++---- |
| 10 | 1 file changed, 34 insertions(+), 4 deletions(-) |
| 11 | |
| 12 | CVE: CVE-2021-4115 |
| 13 | Upstream-Status: Backport [41cb093f554da8772362654a128a84dd8a5542a7] |
| 14 | |
| 15 | diff --git a/src/polkit/polkitsystembusname.c b/src/polkit/polkitsystembusname.c |
| 16 | index 8ed1363..2fbf5f1 100644 |
| 17 | --- a/src/polkit/polkitsystembusname.c |
| 18 | +++ b/src/polkit/polkitsystembusname.c |
| 19 | @@ -62,6 +62,10 @@ enum |
| 20 | PROP_NAME, |
| 21 | }; |
| 22 | |
| 23 | + |
| 24 | +guint8 dbus_call_respond_fails; // has to be global because of callback |
| 25 | + |
| 26 | + |
| 27 | static void subject_iface_init (PolkitSubjectIface *subject_iface); |
| 28 | |
| 29 | G_DEFINE_TYPE_WITH_CODE (PolkitSystemBusName, polkit_system_bus_name, G_TYPE_OBJECT, |
| 30 | @@ -364,6 +368,7 @@ on_retrieved_unix_uid_pid (GObject *src, |
| 31 | if (!v) |
| 32 | { |
| 33 | data->caught_error = TRUE; |
| 34 | + dbus_call_respond_fails += 1; |
| 35 | } |
| 36 | else |
| 37 | { |
| 38 | @@ -405,6 +410,8 @@ polkit_system_bus_name_get_creds_sync (PolkitSystemBusName *system_bus |
| 39 | tmp_context = g_main_context_new (); |
| 40 | g_main_context_push_thread_default (tmp_context); |
| 41 | |
| 42 | + dbus_call_respond_fails = 0; |
| 43 | + |
| 44 | /* Do two async calls as it's basically as fast as one sync call. |
| 45 | */ |
| 46 | g_dbus_connection_call (connection, |
| 47 | @@ -432,11 +439,34 @@ polkit_system_bus_name_get_creds_sync (PolkitSystemBusName *system_bus |
| 48 | on_retrieved_unix_uid_pid, |
| 49 | &data); |
| 50 | |
| 51 | - while (!((data.retrieved_uid && data.retrieved_pid) || data.caught_error)) |
| 52 | - g_main_context_iteration (tmp_context, TRUE); |
| 53 | + while (TRUE) |
| 54 | + { |
| 55 | + /* If one dbus call returns error, we must wait until the other call |
| 56 | + * calls _call_finish(), otherwise fd leak is possible. |
| 57 | + * Resolves: GHSL-2021-077 |
| 58 | + */ |
| 59 | |
| 60 | - if (data.caught_error) |
| 61 | - goto out; |
| 62 | + if ( (dbus_call_respond_fails > 1) ) |
| 63 | + { |
| 64 | + // we got two faults, we can leave |
| 65 | + goto out; |
| 66 | + } |
| 67 | + |
| 68 | + if ((data.caught_error && (data.retrieved_pid || data.retrieved_uid))) |
| 69 | + { |
| 70 | + // we got one fault and the other call finally finished, we can leave |
| 71 | + goto out; |
| 72 | + } |
| 73 | + |
| 74 | + if ( !(data.retrieved_uid && data.retrieved_pid) ) |
| 75 | + { |
| 76 | + g_main_context_iteration (tmp_context, TRUE); |
| 77 | + } |
| 78 | + else |
| 79 | + { |
| 80 | + break; |
| 81 | + } |
| 82 | + } |
| 83 | |
| 84 | if (out_uid) |
| 85 | *out_uid = data.uid; |
| 86 | -- |
| 87 | 2.20.1 |
| 88 | |