polkit: add patches for CVE-2021-4034 and CVE-2021-4115

They were available in polkit master branch and cherry-pick to
0.119 version works so pick the patches.

Signed-off-by: Mikko Rapeli <mikko.rapeli@bmw.de>
This commit is contained in:
Mikko Rapeli 2022-03-25 10:56:26 +02:00 committed by Khem Raj
parent 97c904c765
commit d5eef01fce
3 changed files with 174 additions and 0 deletions

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@ -0,0 +1,84 @@
From 85c2dd9275cdfb369f613089f22733c0f1ba2aec Mon Sep 17 00:00:00 2001
From: Jan Rybar <jrybar@redhat.com>
Date: Tue, 25 Jan 2022 17:21:46 +0000
Subject: [PATCH 1/3] pkexec: local privilege escalation (CVE-2021-4034)
Signed-off-by: Mikko Rapeli <mikko.rapeli@bmw.de>
---
src/programs/pkcheck.c | 5 +++++
src/programs/pkexec.c | 23 ++++++++++++++++++++---
2 files changed, 25 insertions(+), 3 deletions(-)
CVE: CVE-2021-4034
Upstream-Status: Backport [a2bf5c9c83b6ae46cbd5c779d3055bff81ded683]
diff --git a/src/programs/pkcheck.c b/src/programs/pkcheck.c
index f1bb4e1..768525c 100644
--- a/src/programs/pkcheck.c
+++ b/src/programs/pkcheck.c
@@ -363,6 +363,11 @@ main (int argc, char *argv[])
local_agent_handle = NULL;
ret = 126;
+ if (argc < 1)
+ {
+ exit(126);
+ }
+
/* Disable remote file access from GIO. */
setenv ("GIO_USE_VFS", "local", 1);
diff --git a/src/programs/pkexec.c b/src/programs/pkexec.c
index 7698c5c..84e5ef6 100644
--- a/src/programs/pkexec.c
+++ b/src/programs/pkexec.c
@@ -488,6 +488,15 @@ main (int argc, char *argv[])
pid_t pid_of_caller;
gpointer local_agent_handle;
+
+ /*
+ * If 'pkexec' is called THIS wrong, someone's probably evil-doing. Don't be nice, just bail out.
+ */
+ if (argc<1)
+ {
+ exit(127);
+ }
+
ret = 127;
authority = NULL;
subject = NULL;
@@ -614,10 +623,10 @@ main (int argc, char *argv[])
path = g_strdup (pwstruct.pw_shell);
if (!path)
- {
+ {
g_printerr ("No shell configured or error retrieving pw_shell\n");
goto out;
- }
+ }
/* If you change this, be sure to change the if (!command_line)
case below too */
command_line = g_strdup (path);
@@ -636,7 +645,15 @@ main (int argc, char *argv[])
goto out;
}
g_free (path);
- argv[n] = path = s;
+ path = s;
+
+ /* argc<2 and pkexec runs just shell, argv is guaranteed to be null-terminated.
+ * /-less shell shouldn't happen, but let's be defensive and don't write to null-termination
+ */
+ if (argv[n] != NULL)
+ {
+ argv[n] = path;
+ }
}
if (access (path, F_OK) != 0)
{
--
2.20.1

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@ -0,0 +1,88 @@
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

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@ -27,6 +27,8 @@ SRC_URI = "http://www.freedesktop.org/software/polkit/releases/polkit-${PV}.tar.
file://0003-make-netgroup-support-optional.patch \
file://0002-jsauthority-port-to-mozjs-91.patch \
file://0003-jsauthority-ensure-to-call-JS_Init-and-JS_ShutDown-e.patch \
file://0001-pkexec-local-privilege-escalation-CVE-2021-4034.patch \
file://0002-CVE-2021-4115-GHSL-2021-077-fix.patch \
"
SRC_URI[sha256sum] = "c8579fdb86e94295404211285fee0722ad04893f0213e571bd75c00972fd1f5c"