Attachment 88934 Details for Bug 69538 – 0001-PolkitSystemBusName-Retrieve-both-pid-and-uid.patch

[patch] 0001-PolkitSystemBusName-Retrieve-both-pid-and-uid.patch

0001-PolkitSystemBusName-Retrieve-both-pid-and-uid.patch (text/plain), 7.75 KB, created by Colin Walters on 2013-11-09 16:07:57 UTC

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Creator: Colin Walters

Created: 2013-11-09 16:07:57 UTC

Size: 7.75 KB

patch

obsolete

>From ce516eaadd0fc292b92c61e57defa93dbcb8732e Mon Sep 17 00:00:00 2001
>From: Colin Walters <walters@verbum.org>
>Date: Sat, 9 Nov 2013 09:32:52 -0500
>Subject: [PATCH] PolkitSystemBusName: Retrieve both pid and uid
>
>For polkit_system_bus_name_get_process_sync(), as pointed out by
>Miloslav Trmac, we can securely retrieve the owner uid as well from
>the system bus, rather than (racily) looking it up internally.
>
>This avoids use of a deprecated API.
>
>However, this is not a security fix because nothing in the polkit
>codebase itself actually retrieves the uid from the result of this API
>call.  But, it might be useful in the future.
>---
> src/polkit/polkitsystembusname.c |  169 +++++++++++++++++++++++++++-----------
> 1 files changed, 120 insertions(+), 49 deletions(-)
>
>diff --git a/src/polkit/polkitsystembusname.c b/src/polkit/polkitsystembusname.c
>index 51e4a69..af8ae30 100644
>--- a/src/polkit/polkitsystembusname.c
>+++ b/src/polkit/polkitsystembusname.c
>@@ -341,6 +341,116 @@ subject_iface_init (PolkitSubjectIface *subject_iface)
> 
> /* ---------------------------------------------------------------------------------------------------- */
> 
>+typedef struct {
>+  GError **error;
>+  guint retrieved_uid : 1;
>+  guint retrieved_pid : 1;
>+  guint caught_error : 1;
>+
>+  guint32 uid;
>+  guint32 pid;
>+} AsyncGetBusNameCredsData;
>+
>+static void
>+on_retrieved_unix_uid_pid (GObject              *src,
>+			   GAsyncResult         *res,
>+			   gpointer              user_data)
>+{
>+  AsyncGetBusNameCredsData *data = user_data;
>+  GVariant *v;
>+
>+  v = g_dbus_connection_call_finish ((GDBusConnection*)src, res,
>+				     data->caught_error ? NULL : data->error);
>+  if (!v)
>+    {
>+      data->caught_error = TRUE;
>+    }
>+  else
>+    {
>+      guint32 value;
>+      g_variant_get (v, "(u)", &value);
>+      g_variant_unref (v);
>+      if (!data->retrieved_uid)
>+	{
>+	  data->retrieved_uid = TRUE;
>+	  data->uid = value;
>+	}
>+      else
>+	{
>+	  g_assert (!data->retrieved_pid);
>+	  data->retrieved_pid = TRUE;
>+	  data->pid = value;
>+	}
>+    }
>+}
>+
>+static gboolean
>+polkit_system_bus_name_get_creds_sync (PolkitSystemBusName           *system_bus_name,
>+				       guint32                       *out_uid,
>+				       guint32                       *out_pid,
>+				       GCancellable                  *cancellable,
>+				       GError                       **error)
>+{
>+  gboolean ret = FALSE;
>+  AsyncGetBusNameCredsData data = { 0, };
>+  GDBusConnection *connection = NULL;
>+  GMainContext *tmp_context = NULL;
>+
>+  connection = g_bus_get_sync (G_BUS_TYPE_SYSTEM, cancellable, error);
>+  if (connection == NULL)
>+    goto out;
>+
>+  data.error = error;
>+
>+  tmp_context = g_main_context_new ();
>+  g_main_context_push_thread_default (tmp_context);
>+
>+  /* Do two async calls as it's basically as fast as one sync call.
>+   */
>+  g_dbus_connection_call (connection, 
>+			  "org.freedesktop.DBus",       /* name */
>+			  "/org/freedesktop/DBus",      /* object path */
>+			  "org.freedesktop.DBus",       /* interface name */
>+			  "GetConnectionUnixUser",      /* method */
>+			  g_variant_new ("(s)", system_bus_name->name),
>+			  G_VARIANT_TYPE ("(u)"),
>+			  G_DBUS_CALL_FLAGS_NONE,
>+			  -1,
>+			  cancellable,
>+			  on_retrieved_unix_uid_pid,
>+			  &data);
>+  g_dbus_connection_call (connection, 
>+			  "org.freedesktop.DBus",       /* name */
>+			  "/org/freedesktop/DBus",      /* object path */
>+			  "org.freedesktop.DBus",       /* interface name */
>+			  "GetConnectionUnixProcessID", /* method */
>+			  g_variant_new ("(s)", system_bus_name->name),
>+			  G_VARIANT_TYPE ("(u)"),
>+			  G_DBUS_CALL_FLAGS_NONE,
>+			  -1,
>+			  cancellable,
>+			  on_retrieved_unix_uid_pid,
>+			  &data);
>+
>+  while (!((data.retrieved_uid && data.retrieved_pid) || data.caught_error))
>+    g_main_context_iteration (tmp_context, TRUE);
>+
>+  if (out_uid)
>+    *out_uid = data.uid;
>+  if (out_pid)
>+    *out_pid = data.pid;
>+  ret = TRUE;
>+ out:
>+  if (tmp_context)
>+    {
>+      g_main_context_pop_thread_default (tmp_context);
>+      g_main_context_unref (tmp_context);
>+    }
>+  if (connection != NULL)
>+    g_object_unref (connection);
>+  return ret;
>+}
>+
> /**
>  * polkit_system_bus_name_get_process_sync:
>  * @system_bus_name: A #PolkitSystemBusName.
>@@ -357,39 +467,20 @@ polkit_system_bus_name_get_process_sync (PolkitSystemBusName  *system_bus_name,
>                                          GCancellable         *cancellable,
>                                          GError              **error)
> {
>-  GDBusConnection *connection;
>-  PolkitSubject *ret;
>-  GVariant *result;
>+  PolkitSubject *ret = NULL;
>+  GDBusConnection *connection = NULL;
>   guint32 pid;
>+  guint32 uid;
> 
>   g_return_val_if_fail (POLKIT_IS_SYSTEM_BUS_NAME (system_bus_name), NULL);
>   g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), NULL);
>   g_return_val_if_fail (error == NULL || *error == NULL, NULL);
> 
>-  ret = NULL;
>-
>-  connection = g_bus_get_sync (G_BUS_TYPE_SYSTEM, cancellable, error);
>-  if (connection == NULL)
>-    goto out;
>-
>-  result = g_dbus_connection_call_sync (connection,
>-                                        "org.freedesktop.DBus",       /* name */
>-                                        "/org/freedesktop/DBus",      /* object path */
>-                                        "org.freedesktop.DBus",       /* interface name */
>-                                        "GetConnectionUnixProcessID", /* method */
>-                                        g_variant_new ("(s)", system_bus_name->name),
>-                                        G_VARIANT_TYPE ("(u)"),
>-                                        G_DBUS_CALL_FLAGS_NONE,
>-                                        -1,
>-                                        cancellable,
>-                                        error);
>-  if (result == NULL)
>+  if (!polkit_system_bus_name_get_creds_sync (system_bus_name, &uid, &pid,
>+					      cancellable, error))
>     goto out;
> 
>-  g_variant_get (result, "(u)", &pid);
>-  g_variant_unref (result);
>-
>-  ret = polkit_unix_process_new (pid);
>+  ret = polkit_unix_process_new_for_owner (pid, 0, uid);
> 
>  out:
>   if (connection != NULL)
>@@ -413,38 +504,18 @@ polkit_system_bus_name_get_user_sync (PolkitSystemBusName  *system_bus_name,
> 				      GCancellable         *cancellable,
> 				      GError              **error)
> {
>-  GDBusConnection *connection;
>-  PolkitUnixUser *ret;
>-  GVariant *result;
>+  PolkitUnixUser *ret = NULL;
>+  GDBusConnection *connection = NULL;
>   guint32 uid;
> 
>   g_return_val_if_fail (POLKIT_IS_SYSTEM_BUS_NAME (system_bus_name), NULL);
>   g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), NULL);
>   g_return_val_if_fail (error == NULL || *error == NULL, NULL);
> 
>-  ret = NULL;
>-
>-  connection = g_bus_get_sync (G_BUS_TYPE_SYSTEM, cancellable, error);
>-  if (connection == NULL)
>+  if (!polkit_system_bus_name_get_creds_sync (system_bus_name, &uid, NULL,
>+					      cancellable, error))
>     goto out;
> 
>-  result = g_dbus_connection_call_sync (connection,
>-                                        "org.freedesktop.DBus",       /* name */
>-                                        "/org/freedesktop/DBus",      /* object path */
>-                                        "org.freedesktop.DBus",       /* interface name */
>-                                        "GetConnectionUnixUser",      /* method */
>-                                        g_variant_new ("(s)", system_bus_name->name),
>-                                        G_VARIANT_TYPE ("(u)"),
>-                                        G_DBUS_CALL_FLAGS_NONE,
>-                                        -1,
>-                                        cancellable,
>-                                        error);
>-  if (result == NULL)
>-    goto out;
>-
>-  g_variant_get (result, "(u)", &uid);
>-  g_variant_unref (result);
>-
>   ret = (PolkitUnixUser*)polkit_unix_user_new (uid);
> 
>  out:
>-- 
>1.7.1
>

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Attachments on bug 69538: 86078 | 86079 | 88855 | 88856 | 88857 | 88858 | 88934 | 88944 | 88945 | 89028

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