[refpolicy] [PATCH 1/3] X Object Manager policy revisions to xserver.te.

[ewalsh@tycho.nsa.gov (Eamon Walsh)]

X Object Manager policy revisions to xserver.te.

This commit consists of three main parts:

1. Code movement.  There were X object manager-related statements
   scattered somewhat throughout the file; these have been consolidated,
   which resulted in some other statements moving (e.g. iceauth_t).

2. Type changes.  Many of the specific event, extension, and property
   types have been dropped for the time being.  The rootwindow_t and
   remote_xclient_t types have been renamed, and a root_xcolormap_t
   type has been (re-)added.  This is for naming consistency.
   An "xserver_unprotected" alias has been added for use in labeling
   clients whose resources should be globally accessible (e.g. xdm_t).

3. Policy changes.  These are mostly related to devices, which now have
   separate x_keyboard and x_pointer classes.  The "Hacks" section
   has been cleaned up, and various other classes have had the default
   permissions tweaked.

Signed-off-by: Eamon Walsh <ewalsh@tycho.nsa.gov>
---
 policy/modules/services/xserver.te |  273 ++++++++++++++++++++----------------
 1 files changed, 152 insertions(+), 121 deletions(-)

diff --git a/policy/modules/services/xserver.te b/policy/modules/services/xserver.te
index fc421d5..d6c4b95 100644
--- a/policy/modules/services/xserver.te
+++ b/policy/modules/services/xserver.te
@@ -12,6 +12,8 @@ gen_require(`
 	class x_cursor all_x_cursor_perms;
 	class x_client all_x_client_perms;
 	class x_device all_x_device_perms;
+	class x_pointer all_x_pointer_perms;
+	class x_keyboard all_x_keyboard_perms;
 	class x_server all_x_server_perms;
 	class x_extension all_x_extension_perms;
 	class x_resource all_x_resource_perms;
@@ -46,70 +48,53 @@ gen_tunable(xdm_sysadm_login, false)
 ## </desc>
 gen_tunable(xserver_object_manager, false)
 
-attribute input_xevent_type;
-attribute xserver_unconfined_type;
 attribute x_domain;
-attribute x_userdomain;
-attribute xproperty_type;
-attribute xselection_type;
-attribute xextension_type;
-attribute xevent_type;
 
-type accelgraphics_xext_t, xextension_type;
+# X Events
+attribute xevent_type;
+attribute input_xevent_type;
+type xevent_t, xevent_type;
 type client_xevent_t, xevent_type;
+type input_xevent_t, xevent_type, input_xevent_type;
+
+# X Extensions
+attribute xextension_type;
+type xextension_t, xextension_type;
+type security_xextension_t, xextension_type;
+
+# X Properties
+attribute xproperty_type;
+type xproperty_t, xproperty_type;
+type seclabel_xproperty_t, xproperty_type;
 type clipboard_xproperty_t, xproperty_type;
-type clipboard_xselection_t, xselection_type;
-type debug_xext_t, xextension_type;
-type directhw_xext_t alias disallowed_xext_t, xextension_type;
-type focus_xevent_t, xevent_type;
 
-type iceauth_t;
-type iceauth_exec_t;
-typealias iceauth_t alias { user_iceauth_t staff_iceauth_t sysadm_iceauth_t };
-typealias iceauth_t alias { auditadm_iceauth_t secadm_iceauth_t };
-application_domain(iceauth_t, iceauth_exec_t)
-ubac_constrained(iceauth_t)
+# X Selections
+attribute xselection_type;
+type xselection_t, xselection_type;
+type clipboard_xselection_t, xselection_type;
+#type settings_xselection_t, xselection_type;
+#type dbus_xselection_t, xselection_type;
 
-type iceauth_home_t;
-typealias iceauth_home_t alias { user_iceauth_home_t staff_iceauth_home_t sysadm_iceauth_home_t };
-typealias iceauth_home_t alias { auditadm_iceauth_home_t secadm_iceauth_home_t };
-files_poly_member(iceauth_home_t)
-userdom_user_home_content(iceauth_home_t)
+# X Drawables
+attribute xdrawable_type;
+attribute xcolormap_type;
+type root_xdrawable_t, xdrawable_type;
+type root_xcolormap_t, xcolormap_type;
 
-type info_xproperty_t, xproperty_type;
-type input_xevent_t, xevent_type;
-type manage_xevent_t, xevent_type;
-type output_xext_t, xextension_type;
-type property_xevent_t, xevent_type;
-type remote_xclient_t;
-
-type rootwindow_t;
-typealias rootwindow_t alias { user_rootwindow_t staff_rootwindow_t sysadm_rootwindow_t };
-typealias rootwindow_t alias { auditadm_rootwindow_t secadm_rootwindow_t };
-ubac_constrained(rootwindow_t)
-
-type screensaver_xext_t, xextension_type;
-type security_xext_t, xextension_type;
-type shmem_xext_t, xextension_type;
-type std_xext_t, xextension_type;
-type video_xext_t, xextension_type;
-type unknown_xevent_t, xevent_type;
+attribute xserver_unconfined_type;
+attribute xserver_unprotected_type;
 
+xserver_object_types_template(root)
 xserver_object_types_template(user)
+
 typealias user_xproperty_t alias { staff_xproperty_t sysadm_xproperty_t };
 typealias user_xproperty_t alias { auditadm_xproperty_t secadm_xproperty_t };
 typealias user_input_xevent_t alias { staff_input_xevent_t sysadm_input_xevent_t };
 typealias user_input_xevent_t alias { auditadm_input_xevent_t secadm_input_xevent_t };
-typealias user_property_xevent_t alias { staff_property_xevent_t sysadm_property_xevent_t };
-typealias user_property_xevent_t alias { auditadm_property_xevent_t secadm_property_xevent_t };
-typealias user_focus_xevent_t alias { staff_focus_xevent_t sysadm_focus_xevent_t };
-typealias user_focus_xevent_t alias { auditadm_focus_xevent_t secadm_focus_xevent_t };
-typealias user_manage_xevent_t alias { staff_manage_xevent_t sysadm_manage_xevent_t };
-typealias user_manage_xevent_t alias { auditadm_manage_xevent_t secadm_manage_xevent_t };
-typealias user_default_xevent_t alias { staff_default_xevent_t sysadm_default_xevent_t };
-typealias user_default_xevent_t alias { auditadm_default_xevent_t secadm_default_xevent_t };
-typealias user_client_xevent_t alias { staff_client_xevent_t sysadm_client_xevent_t };
-typealias user_client_xevent_t alias { auditadm_client_xevent_t secadm_client_xevent_t };
+
+type remote_t;
+xserver_object_types_template(remote)
+xserver_common_x_domain_template(remote,remote_t)
 
 type user_fonts_t;
 typealias user_fonts_t alias { staff_fonts_t sysadm_fonts_t };
@@ -126,10 +111,18 @@ typealias user_fonts_config_t alias { staff_fonts_config_t sysadm_fonts_config_t
 typealias user_fonts_config_t alias { auditadm_fonts_config_t secadm_fonts_config_t };
 userdom_user_home_content(user_fonts_config_t)
 
-type xevent_t alias default_xevent_t, xevent_type;
-type xext_t alias unknown_xext_t, xextension_type;
-type xproperty_t alias default_xproperty_t, xproperty_type;
-type xselection_t alias default_xselection_t, xselection_type;
+type iceauth_t;
+type iceauth_exec_t;
+typealias iceauth_t alias { user_iceauth_t staff_iceauth_t sysadm_iceauth_t };
+typealias iceauth_t alias { auditadm_iceauth_t secadm_iceauth_t };
+application_domain(iceauth_t, iceauth_exec_t)
+ubac_constrained(iceauth_t)
+
+type iceauth_home_t;
+typealias iceauth_home_t alias { user_iceauth_home_t staff_iceauth_home_t sysadm_iceauth_home_t };
+typealias iceauth_home_t alias { auditadm_iceauth_home_t secadm_iceauth_home_t };
+files_poly_member(iceauth_home_t)
+userdom_user_home_content(iceauth_home_t)
 
 type xauth_t;
 type xauth_exec_t;
@@ -161,6 +154,10 @@ type xdm_exec_t;
 auth_login_pgm_domain(xdm_t)
 init_domain(xdm_t, xdm_exec_t)
 init_daemon_domain(xdm_t, xdm_exec_t)
+xserver_object_types_template(xdm)
+xserver_common_x_domain_template(xdm, xdm_t)
+xserver_unconfined(xdm_t)
+xserver_unprotected(xdm_t)
 
 type xdm_lock_t;
 files_lock_file(xdm_lock_t)
@@ -190,8 +187,6 @@ type xserver_t;
 type xserver_exec_t;
 typealias xserver_t alias { user_xserver_t staff_xserver_t sysadm_xserver_t };
 typealias xserver_t alias { auditadm_xserver_t secadm_xserver_t xdm_xserver_t };
-xserver_object_types_template(xdm)
-xserver_common_x_domain_template(xdm, xdm_t)
 init_system_domain(xserver_t, xserver_exec_t)
 ubac_constrained(xserver_t)
 
@@ -579,6 +574,14 @@ optional_policy(`
 # X server local policy
 #
 
+# X Object Manager rules
+type_transition xserver_t xserver_t:x_drawable root_xdrawable_t;
+type_transition xserver_t xserver_t:x_colormap root_xcolormap_t;
+type_transition root_xdrawable_t input_xevent_t:x_event root_input_xevent_t;
+
+allow xserver_t { root_xdrawable_t x_domain }:x_drawable send;
+allow xserver_t input_xevent_t:x_event send;
+
 # setuid/setgid for the wrapper program to change UID
 # sys_rawio is for iopl access - should not be needed for frame-buffer
 # sys_admin, locking shared mem?  chowning IPC message queues or semaphores?
@@ -603,20 +606,6 @@ allow xserver_t self:unix_stream_socket { create_stream_socket_perms connectto }
 allow xserver_t self:tcp_socket create_stream_socket_perms;
 allow xserver_t self:udp_socket create_socket_perms;
 
-# Device rules
-allow x_domain xserver_t:x_device { read getattr use setattr setfocus grab bell };
-
-allow xserver_t { input_xevent_t input_xevent_type }:x_event send;
-
-domtrans_pattern(xserver_t, xauth_exec_t, xauth_t)
-
-allow xserver_t xauth_home_t:file read_file_perms;
-
-# Labeling rules for root windows and colormaps
-type_transition xserver_t xserver_t:{ x_drawable x_colormap } rootwindow_t;
-
-allow xserver_t { rootwindow_t x_domain }:x_drawable send;
-
 manage_dirs_pattern(xserver_t, xserver_tmp_t, xserver_tmp_t)
 manage_files_pattern(xserver_t, xserver_tmp_t, xserver_tmp_t)
 manage_sock_files_pattern(xserver_t, xserver_tmp_t, xserver_tmp_t)
@@ -635,6 +624,9 @@ manage_files_pattern(xserver_t, xkb_var_lib_t, xkb_var_lib_t)
 manage_lnk_files_pattern(xserver_t, xkb_var_lib_t, xkb_var_lib_t)
 files_search_var_lib(xserver_t)
 
+domtrans_pattern(xserver_t, xauth_exec_t, xauth_t)
+allow xserver_t xauth_home_t:file read_file_perms;
+
 # Create files in /var/log with the xserver_log_t type.
 manage_files_pattern(xserver_t, xserver_log_t, xserver_log_t)
 logging_log_filetrans(xserver_t, xserver_log_t, file)
@@ -752,15 +744,17 @@ tunable_policy(`!xserver_object_manager',`
 	# but typeattribute doesnt work in conditionals
 
 	allow xserver_t xserver_t:x_server *;
-	allow xserver_t { x_domain rootwindow_t }:x_drawable *;
+	allow xserver_t { x_domain root_xdrawable_t }:x_drawable *;
 	allow xserver_t xserver_t:x_screen *;
 	allow xserver_t x_domain:x_gc *;
-	allow xserver_t { x_domain rootwindow_t }:x_colormap *;
+	allow xserver_t { x_domain root_xcolormap_t }:x_colormap *;
 	allow xserver_t xproperty_type:x_property *;
 	allow xserver_t xselection_type:x_selection *;
 	allow xserver_t x_domain:x_cursor *;
-	allow xserver_t { x_domain remote_xclient_t }:x_client *;
+	allow xserver_t x_domain:x_client *;
 	allow xserver_t { x_domain xserver_t }:x_device *;
+	allow xserver_t { x_domain xserver_t }:x_pointer *;
+	allow xserver_t { x_domain xserver_t }:x_keyboard *;
 	allow xserver_t xextension_type:x_extension *;
 	allow xserver_t { x_domain xserver_t }:x_resource *;
 	allow xserver_t xevent_type:{ x_event x_synthetic_event } *;
@@ -863,112 +857,149 @@ optional_policy(`
 #
 
 # Hacks
-# everyone can get the input focus of everyone else
-# this is a fundamental brokenness in the X protocol
-allow x_domain { x_domain xserver_t }:x_device getfocus;
-# everyone can grab the server
-# everyone does it, it is basically a free DOS attack
-allow x_domain xserver_t:x_server grab;
-# everyone can get the font path, etc.
-# this could leak out sensitive information
-allow x_domain xserver_t:x_server getattr;
 # everyone can do override-redirect windows.
 # this could be used to spoof labels
 allow x_domain self:x_drawable override;
-# everyone can receive management events on the root window
-# allows to know when new windows appear, among other things
-allow x_domain manage_xevent_t:x_event receive;
+# firefox gets nosy with other people's windows
+allow x_domain x_domain:x_drawable { list_child receive };
 
 # X Server
-# can read server-owned resources
-allow x_domain xserver_t:x_resource read;
+# can get X server attributes
+allow x_domain xserver_t:x_server getattr;
+# can grab the server
+allow x_domain xserver_t:x_server grab;
+# can read and write server-owned generic resources
+allow x_domain xserver_t:x_resource { read write };
 # can mess with own clients
-allow x_domain self:x_client { manage destroy };
+allow x_domain self:x_client { getattr manage destroy };
 
 # X Protocol Extensions
-allow x_domain std_xext_t:x_extension { query use };
-allow x_domain shmem_xext_t:x_extension { query use };
-dontaudit x_domain xextension_type:x_extension { query use };
+allow x_domain xextension_t:x_extension { query use };
+allow x_domain security_xextension_t:x_extension { query use };
 
 # X Properties
-# can read and write cut buffers
-allow x_domain clipboard_xproperty_t:x_property { create read write append };
-# can read info properties
-allow x_domain info_xproperty_t:x_property read;
 # can change properties of root window
-allow x_domain rootwindow_t:x_drawable { list_property get_property set_property };
-# can change properties of own windows
+allow x_domain root_xdrawable_t:x_drawable { list_property get_property set_property };
+# can change properties of my own windows
 allow x_domain self:x_drawable { list_property get_property set_property };
+# can read and write cut buffers
+allow x_domain clipboard_xproperty_t:x_property { create read write append };
+# can read security labels
+allow x_domain seclabel_xproperty_t:x_property { getattr read };
+# can change all other properties
+allow x_domain xproperty_t:x_property { getattr create read write append destroy };
 
 # X Windows
 # operations allowed on root windows
-allow x_domain rootwindow_t:x_drawable { getattr list_child add_child remove_child send receive };
+allow x_domain root_xdrawable_t:x_drawable { getattr setattr list_child add_child remove_child send receive hide show };
 # operations allowed on my windows
 allow x_domain self:x_drawable { create destroy getattr setattr read write show hide list_child add_child remove_child manage send receive };
+allow x_domain self:x_drawable { blend };
+# operations allowed on all windows
+allow x_domain x_domain:x_drawable { getattr get_property set_property remove_child };
 
 # X Colormaps
 # can use the default colormap
-allow x_domain rootwindow_t:x_colormap { read use add_color };
+allow x_domain root_xcolormap_t:x_colormap { read use add_color remove_color install uninstall };
+# can create and use colormaps
+allow x_domain self:x_colormap *;
+
+# X Devices
+# operations allowed on my own devices
+allow x_domain self:{ x_device x_pointer x_keyboard } *;
+# operations allowed on generic devices
+allow x_domain xserver_t:x_device { use getattr setattr getfocus setfocus bell grab freeze force_cursor };
+# operations allowed on core keyboard
+allow x_domain xserver_t:x_keyboard { use getattr setattr getfocus setfocus bell grab };
+# operations allowed on core pointer
+allow x_domain xserver_t:x_pointer { read use getattr setattr getfocus setfocus bell grab freeze force_cursor };
+
+# all devices can generate input events
+allow x_domain root_xdrawable_t:x_drawable send;
+allow x_domain x_domain:x_drawable send;
+allow x_domain input_xevent_t:x_event send;
+
+# dontaudit keyloggers repeatedly polling
+#dontaudit x_domain xserver_t:x_keyboard read;
 
 # X Input
-# can receive certain root window events
-allow x_domain focus_xevent_t:x_event receive;
-allow x_domain property_xevent_t:x_event receive;
-allow x_domain client_xevent_t:x_synthetic_event receive;
-allow x_domain manage_xevent_t:x_synthetic_event receive;
+# can receive default events
+allow x_domain xevent_t:{ x_event x_synthetic_event } receive;
+# can receive ICCCM events
+allow x_domain client_xevent_t:{ x_event x_synthetic_event } receive;
 # can send ICCCM events to the root window
-allow x_domain manage_xevent_t:x_synthetic_event send;
 allow x_domain client_xevent_t:x_synthetic_event send;
+# can receive root window input events
+allow x_domain root_input_xevent_t:x_event receive;
+
 # X Selections
 # can use the clipboard
 allow x_domain clipboard_xselection_t:x_selection { getattr setattr read };
-# can query all other selections
-allow x_domain xselection_t:x_selection { getattr read };
+# can use default selections
+allow x_domain xselection_t:x_selection { getattr setattr read };
 
 # Other X Objects
 # can create and use cursors
 allow x_domain self:x_cursor *;
 # can create and use graphics contexts
 allow x_domain self:x_gc *;
-# can create and use colormaps
-allow x_domain self:x_colormap *;
 # can read and write own objects
 allow x_domain self:x_resource { read write };
+# can mess with the screensaver
+allow x_domain xserver_t:x_screen { getattr saver_getattr };
+
+########################################
+#
+# Rules for unprotected access to a domain
+#
+
+allow x_domain xserver_unprotected_type:x_drawable *;
+allow x_domain xserver_unprotected_type:x_gc *;
+allow x_domain xserver_unprotected_type:x_colormap *;
+allow x_domain xserver_unprotected_type:x_property *;
+allow x_domain xserver_unprotected_type:x_cursor *;
+allow x_domain xserver_unprotected_type:x_client *;
+allow x_domain xserver_unprotected_type:x_device *;
+allow x_domain xserver_unprotected_type:x_resource *;
+
+########################################
+#
+# Rules for unconfined access to this module
+#
 
 tunable_policy(`! xserver_object_manager',`
 	# should be xserver_unconfined(x_domain),
 	# but typeattribute doesnt work in conditionals
 
 	allow x_domain xserver_t:x_server *;
-	allow x_domain { x_domain rootwindow_t }:x_drawable *;
+	allow x_domain xdrawable_type:x_drawable *;
 	allow x_domain xserver_t:x_screen *;
 	allow x_domain x_domain:x_gc *;
-	allow x_domain { x_domain rootwindow_t }:x_colormap *;
+	allow x_domain xcolormap_type:x_colormap *;
 	allow x_domain xproperty_type:x_property *;
 	allow x_domain xselection_type:x_selection *;
 	allow x_domain x_domain:x_cursor *;
-	allow x_domain { x_domain remote_xclient_t }:x_client *;
+	allow x_domain x_domain:x_client *;
 	allow x_domain { x_domain xserver_t }:x_device *;
+	allow x_domain { x_domain xserver_t }:x_pointer *;
+	allow x_domain { x_domain xserver_t }:x_keyboard *;
 	allow x_domain xextension_type:x_extension *;
 	allow x_domain { x_domain xserver_t }:x_resource *;
 	allow x_domain xevent_type:{ x_event x_synthetic_event } *;
 ')
 
-########################################
-#
-# Rules for unconfined access to this module
-#
-
 allow xserver_unconfined_type xserver_t:x_server *;
-allow xserver_unconfined_type { x_domain rootwindow_t }:x_drawable *;
+allow xserver_unconfined_type xdrawable_type:x_drawable *;
 allow xserver_unconfined_type xserver_t:x_screen *;
 allow xserver_unconfined_type x_domain:x_gc *;
-allow xserver_unconfined_type { x_domain rootwindow_t }:x_colormap *;
+allow xserver_unconfined_type xcolormap_type:x_colormap *;
 allow xserver_unconfined_type xproperty_type:x_property *;
 allow xserver_unconfined_type xselection_type:x_selection *;
 allow xserver_unconfined_type x_domain:x_cursor *;
-allow xserver_unconfined_type { x_domain remote_xclient_t }:x_client *;
+allow xserver_unconfined_type x_domain:x_client *;
 allow xserver_unconfined_type { x_domain xserver_t }:x_device *;
+allow xserver_unconfined_type { x_domain xserver_t }:x_pointer *;
+allow xserver_unconfined_type { x_domain xserver_t }:x_keyboard *;
 allow xserver_unconfined_type xextension_type:x_extension *;
 allow xserver_unconfined_type { x_domain xserver_t }:x_resource *;
 allow xserver_unconfined_type xevent_type:{ x_event x_synthetic_event } *;
-- 
1.6.5.rc2



-- 

Eamon Walsh 
National Security Agency