From 35af308b530f36c1a0a912387106a59b3ab92027 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Mon, 3 Dec 2018 10:28:58 +0100
Subject: [PATCH 1/2] Use default of -1 for uid/gid in class initialization
This doesn't seem to change anything in polkitd behaviour, but it
seems cleaner to default to -1 which here means "unset".
---
src/polkit/polkitunixgroup.c | 4 ++--
src/polkit/polkitunixuser.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/src/polkit/polkitunixgroup.c b/src/polkit/polkitunixgroup.c
index c57a1aa..095cca0 100644
--- a/src/polkit/polkitunixgroup.c
+++ b/src/polkit/polkitunixgroup.c
@@ -131,9 +131,9 @@ polkit_unix_group_class_init (PolkitUnixGroupClass *klass)
g_param_spec_int ("gid",
"Group ID",
"The UNIX group ID",
- 0,
+ -1,
G_MAXINT,
- 0,
+ -1,
G_PARAM_CONSTRUCT |
G_PARAM_READWRITE |
G_PARAM_STATIC_NAME |
diff --git a/src/polkit/polkitunixuser.c b/src/polkit/polkitunixuser.c
index 8bfd3a1..a5285f4 100644
--- a/src/polkit/polkitunixuser.c
+++ b/src/polkit/polkitunixuser.c
@@ -144,9 +144,9 @@ polkit_unix_user_class_init (PolkitUnixUserClass *klass)
g_param_spec_int ("uid",
"User ID",
"The UNIX user ID",
- 0,
+ -1,
G_MAXINT,
- 0,
+ -1,
G_PARAM_CONSTRUCT |
G_PARAM_READWRITE |
G_PARAM_STATIC_NAME |
--
2.18.1
From fbaab32cb4ed9ed5f1e3eea6cd317d443aa427dc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Mon, 3 Dec 2018 12:51:26 +0100
Subject: [PATCH 2/2] Check gid and uid initalization in PolkitUnixUser and
Group objects
When a user or group above INT32_MAX is created, the numeric uid or
gid wraps around to negative when the value is assigned to gint, and
polkit gets confused. Let's refuse such uids and gids.
This patch just refuses to initialize uid and gid values to negative.
A nicer fix is to change the underlying type to e.g. gint64 to allow
the full range of values in uid_t and gid_t to be represented. But
this cannot be done without breaking the API, so likely new functions
will have to be added (a polkit_unix_user_new variant that takes a
gint64, and the same for _group_new, _set_uid, _get_uid, _set_gid,
_get_gid, etc.). This will require a bigger patch.
Fixes https://gitlab.freedesktop.org/polkit/polkit/issues/74.
Example sessions from uid=4000000000:
Dec 03 14:35:08 krowka polkitd[21432]: system-bus-name::1.41869 is inquiring whether system-bus-name::1.79432 is authorized for org.freedesktop.systemd1.manage-units
Dec 03 14:35:08 krowka polkitd[21432]: user of caller is unix-user:root
Dec 03 14:35:08 krowka polkitd[21432]: polkit_unix_user_new: assertion 'uid >= 0' failed
Dec 03 14:35:08 krowka polkitd[21432]: polkit_identity_to_string: assertion 'POLKIT_IS_IDENTITY (identity)' failed
Dec 03 14:35:08 krowka polkitd[21432]: user of subject is (null)
Dec 03 14:35:08 krowka polkitd[21432]: polkit_identity_equal: assertion 'POLKIT_IS_IDENTITY (b)' failed
Dec 03 14:35:08 krowka polkitd[21432]: checking whether system-bus-name::1.79432 is authorized for org.freedesktop.systemd1.manage-units
Dec 03 14:35:08 krowka polkitd[21432]: polkit_unix_user_new: assertion 'uid >= 0' failed
Dec 03 14:35:08 krowka polkitd[21432]:
Dec 03 14:35:08 krowka polkitd[21432]: polkit_authorization_result_get_is_challenge: assertion 'POLKIT_IS_AUTHORIZATION_RESULT (result)' failed
Dec 03 14:35:08 krowka polkitd[21432]: g_object_ref: assertion 'G_IS_OBJECT (object)' failed
Dec 03 14:35:08 krowka polkitd[21432]: g_object_ref: assertion 'G_IS_OBJECT (object)' failed
Dec 03 14:35:08 krowka polkitd[21432]: polkit_authorization_result_get_details: assertion 'POLKIT_IS_AUTHORIZATION_RESULT (result)' failed
Dec 03 14:35:08 krowka polkitd[21432]: polkit_authorization_result_get_is_challenge: assertion 'POLKIT_IS_AUTHORIZATION_RESULT (result)' failed
Dec 03 14:35:08 krowka polkitd[21432]: polkit_authorization_result_get_is_authorized: assertion 'POLKIT_IS_AUTHORIZATION_RESULT (result)' failed
Dec 03 14:35:08 krowka polkitd[21432]: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
Dec 03 14:35:08 krowka polkitd[21432]: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
---
src/polkit/polkitunixgroup.c | 9 ++++++++-
src/polkit/polkitunixuser.c | 7 +++++++
2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/src/polkit/polkitunixgroup.c b/src/polkit/polkitunixgroup.c
index 095cca0..53db862 100644
--- a/src/polkit/polkitunixgroup.c
+++ b/src/polkit/polkitunixgroup.c
@@ -71,6 +71,7 @@ G_DEFINE_TYPE_WITH_CODE (PolkitUnixGroup, polkit_unix_group, G_TYPE_OBJECT,
static void
polkit_unix_group_init (PolkitUnixGroup *unix_group)
{
+ unix_group->gid = -1;
}
static void
@@ -100,11 +101,14 @@ polkit_unix_group_set_property (GObject *object,
GParamSpec *pspec)
{
PolkitUnixGroup *unix_group = POLKIT_UNIX_GROUP (object);
+ gint val;
switch (prop_id)
{
case PROP_GID:
- unix_group->gid = g_value_get_int (value);
+ val = g_value_get_int (value);
+ g_return_if_fail (val >= 0);
+ unix_group->gid = val;
break;
default:
@@ -169,6 +173,7 @@ polkit_unix_group_set_gid (PolkitUnixGroup *group,
gint gid)
{
g_return_if_fail (POLKIT_IS_UNIX_GROUP (group));
+ g_return_if_fail (gid >= 0);
group->gid = gid;
}
@@ -183,6 +188,8 @@ polkit_unix_group_set_gid (PolkitUnixGroup *group,
PolkitIdentity *
polkit_unix_group_new (gint gid)
{
+ g_return_val_if_fail (gid >= 0, NULL);
+
return POLKIT_IDENTITY (g_object_new (POLKIT_TYPE_UNIX_GROUP,
"gid", gid,
NULL));
diff --git a/src/polkit/polkitunixuser.c b/src/polkit/polkitunixuser.c
index a5285f4..ef6403e 100644
--- a/src/polkit/polkitunixuser.c
+++ b/src/polkit/polkitunixuser.c
@@ -72,6 +72,7 @@ G_DEFINE_TYPE_WITH_CODE (PolkitUnixUser, polkit_unix_user, G_TYPE_OBJECT,
static void
polkit_unix_user_init (PolkitUnixUser *unix_user)
{
+ unix_user->uid = -1;
unix_user->name = NULL;
}
@@ -112,10 +113,13 @@ polkit_unix_user_set_property (GObject *object,
GParamSpec *pspec)
{
PolkitUnixUser *unix_user = POLKIT_UNIX_USER (object);
+ gint val;
switch (prop_id)
{
case PROP_UID:
+ val = g_value_get_int (value);
+ g_return_if_fail (val >= 0);
unix_user->uid = g_value_get_int (value);
break;
@@ -182,6 +186,7 @@ polkit_unix_user_set_uid (PolkitUnixUser *user,
gint uid)
{
g_return_if_fail (POLKIT_IS_UNIX_USER (user));
+ g_return_if_fail (uid >= 0);
user->uid = uid;
}
@@ -196,6 +201,8 @@ polkit_unix_user_set_uid (PolkitUnixUser *user,
PolkitIdentity *
polkit_unix_user_new (gint uid)
{
+ g_return_val_if_fail (uid >= 0, NULL);
+
return POLKIT_IDENTITY (g_object_new (POLKIT_TYPE_UNIX_USER,
"uid", uid,
NULL));
--
2.18.1
