2021-10-09 10:05:12

by Russell Coker

[permalink] [raw]
Subject: [PATCH] strict policy patches

Allow user domains to read kernel sysctls and crypto sysctls.

Add userdom_write_all_user_runtime_named_sockets interface (for pulseaudio_t).

Give sysadm_t more access.

Give dbus domains a little more access.

Allow ssh agent to write to an inherited log file from the X server.

Make systemd_analyze_exec_t an alias for bin_t and remove systemd_analyze_t
omain.

Allow system cronjobs to read fs sysctls.

Signed-off-by: Russell Coker <[email protected]>

Index: refpolicy-2.20210908/policy/modules/system/userdomain.if
===================================================================
--- refpolicy-2.20210908.orig/policy/modules/system/userdomain.if
+++ refpolicy-2.20210908/policy/modules/system/userdomain.if
@@ -68,6 +68,8 @@ template(`userdom_base_user_template',`
dontaudit $1_t user_tty_device_t:chr_file ioctl;

kernel_read_kernel_sysctls($1_t)
+ kernel_read_crypto_sysctls($1_t)
+ kernel_read_vm_overcommit_sysctl($1_t)
kernel_dontaudit_list_unlabeled($1_t)
kernel_dontaudit_getattr_unlabeled_files($1_t)
kernel_dontaudit_getattr_unlabeled_symlinks($1_t)
@@ -3558,6 +3560,25 @@ interface(`userdom_delete_all_user_runti
')

########################################
+## <summary>
+## write user runtime socket files
+## </summary>
+## <param name="domain">
+## <summary>
+## Domain allowed access.
+## </summary>
+## </param>
+#
+interface(`userdom_write_all_user_runtime_named_sockets',`
+ gen_require(`
+ attribute user_runtime_content_type;
+ ')
+
+ allow $1 user_runtime_content_type:dir list_dir_perms;
+ allow $1 user_runtime_content_type:sock_file write;
+')
+
+########################################
## <summary>
## delete user runtime files
## </summary>
Index: refpolicy-2.20210908/policy/modules/roles/sysadm.te
===================================================================
--- refpolicy-2.20210908.orig/policy/modules/roles/sysadm.te
+++ refpolicy-2.20210908/policy/modules/roles/sysadm.te
@@ -33,11 +33,22 @@ ifndef(`enable_mls',`
# Local policy
#

+allow sysadm_t self:netlink_generic_socket { create setopt bind write read };
+
+# for ptrace
+allow sysadm_t self:netlink_tcpdiag_socket { create write nlmsg_read read };
+
+allow sysadm_t self:capability audit_write;
+allow sysadm_t self:system status;
+
corecmd_exec_shell(sysadm_t)

corenet_ib_access_unlabeled_pkeys(sysadm_t)
corenet_ib_manage_subnet_unlabeled_endports(sysadm_t)

+domain_getsched_all_domains(sysadm_t)
+
+dev_read_cpuid(sysadm_t)
dev_read_kmsg(sysadm_t)

logging_watch_all_logs(sysadm_t)
@@ -58,6 +69,9 @@ init_admin(sysadm_t)
userdom_manage_user_home_dirs(sysadm_t)
userdom_home_filetrans_user_home_dir(sysadm_t)

+# for systemd-analyze
+files_get_etc_unit_status(sysadm_t)
+
ifdef(`direct_sysadm_daemon',`
optional_policy(`
init_run_daemon(sysadm_t, sysadm_r)
@@ -1033,6 +1047,10 @@ optional_policy(`
')

optional_policy(`
+ systemd_dbus_chat_logind(sysadm_t)
+')
+
+optional_policy(`
tboot_run_txtstat(sysadm_t, sysadm_r)
')

@@ -1100,6 +1118,7 @@ optional_policy(`
')

optional_policy(`
+ dev_rw_generic_usb_dev(sysadm_t)
usbmodules_run(sysadm_t, sysadm_r)
')

Index: refpolicy-2.20210908/policy/modules/services/xserver.if
===================================================================
--- refpolicy-2.20210908.orig/policy/modules/services/xserver.if
+++ refpolicy-2.20210908/policy/modules/services/xserver.if
@@ -100,6 +100,7 @@ interface(`xserver_restricted_role',`
xserver_xsession_entry_type($2)
xserver_dontaudit_write_log($2)
xserver_stream_connect_xdm($2)
+ xserver_use_user_fonts($2)
# certain apps want to read xdm.pid file
xserver_read_xdm_runtime_files($2)
# gnome-session creates socket under /tmp/.ICE-unix/
@@ -141,7 +142,7 @@ interface(`xserver_role',`
gen_require(`
type iceauth_home_t, xserver_t, xserver_tmp_t, xserver_tmpfs_t, xauth_home_t;
type user_fonts_t, user_fonts_cache_t, user_fonts_config_t;
- type mesa_shader_cache_t;
+ type mesa_shader_cache_t, xdm_t;
')

xserver_restricted_role($1, $2)
@@ -184,6 +185,8 @@ interface(`xserver_role',`

xserver_read_xkb_libs($2)

+ allow $2 xdm_t:unix_stream_socket accept;
+
optional_policy(`
xdg_cache_filetrans($2, mesa_shader_cache_t, dir, "mesa_shader_cache")
')
@@ -1224,6 +1227,7 @@ interface(`xserver_read_xkb_libs',`
allow $1 xkb_var_lib_t:dir list_dir_perms;
read_files_pattern($1, xkb_var_lib_t, xkb_var_lib_t)
read_lnk_files_pattern($1, xkb_var_lib_t, xkb_var_lib_t)
+ allow $1 xkb_var_lib_t:file map;
')

########################################
Index: refpolicy-2.20210908/policy/modules/services/dbus.if
===================================================================
--- refpolicy-2.20210908.orig/policy/modules/services/dbus.if
+++ refpolicy-2.20210908/policy/modules/services/dbus.if
@@ -85,6 +85,7 @@ template(`dbus_role_template',`

allow $3 $1_dbusd_t:unix_stream_socket connectto;
allow $3 $1_dbusd_t:dbus { send_msg acquire_svc };
+ allow $1_dbusd_t $3:dbus send_msg;
allow $3 $1_dbusd_t:fd use;

dontaudit $1_dbusd_t self:process getcap;
@@ -103,9 +104,13 @@ template(`dbus_role_template',`

allow $1_dbusd_t $3:process sigkill;

+ allow $1_dbusd_t self:process getcap;
+
corecmd_bin_domtrans($1_dbusd_t, $3)
corecmd_shell_domtrans($1_dbusd_t, $3)

+ dev_read_sysfs($1_dbusd_t)
+
auth_use_nsswitch($1_dbusd_t)

ifdef(`hide_broken_symptoms',`
@@ -117,6 +122,15 @@ template(`dbus_role_template',`
systemd_user_daemon_domain($1, dbusd_exec_t, $1_dbusd_t)
systemd_user_unix_stream_activated_socket($1_dbusd_t, session_dbusd_runtime_t)
')
+
+ optional_policy(`
+ init_dbus_chat($1_dbusd_t)
+ dbus_system_bus_client($1_dbusd_t)
+ ')
+
+ optional_policy(`
+ xdg_read_data_files($1_dbusd_t)
+ ')
')

#######################################
Index: refpolicy-2.20210908/policy/modules/services/ssh.if
===================================================================
--- refpolicy-2.20210908.orig/policy/modules/services/ssh.if
+++ refpolicy-2.20210908/policy/modules/services/ssh.if
@@ -440,6 +440,7 @@ template(`ssh_role_template',`
xserver_use_xdm_fds($1_ssh_agent_t)
xserver_rw_xdm_pipes($1_ssh_agent_t)
xserver_sigchld_xdm($1_ssh_agent_t)
+ xserver_write_inherited_xsession_log($1_ssh_agent_t)
')
')

Index: refpolicy-2.20210908/policy/modules/kernel/corecommands.te
===================================================================
--- refpolicy-2.20210908.orig/policy/modules/kernel/corecommands.te
+++ refpolicy-2.20210908/policy/modules/kernel/corecommands.te
@@ -13,7 +13,7 @@ attribute exec_type;
#
# bin_t is the type of files in the system bin/sbin directories.
#
-type bin_t alias { ls_exec_t sbin_t };
+type bin_t alias { ls_exec_t sbin_t systemd_analyze_exec_t };
corecmd_executable_file(bin_t)
dev_associate(bin_t) #For /dev/MAKEDEV

Index: refpolicy-2.20210908/policy/modules/system/systemd.te
===================================================================
--- refpolicy-2.20210908.orig/policy/modules/system/systemd.te
+++ refpolicy-2.20210908/policy/modules/system/systemd.te
@@ -65,10 +65,6 @@ type systemd_activate_t;
type systemd_activate_exec_t;
init_system_domain(systemd_activate_t, systemd_activate_exec_t)

-type systemd_analyze_t;
-type systemd_analyze_exec_t;
-init_daemon_domain(systemd_analyze_t, systemd_analyze_exec_t)
-
type systemd_backlight_t;
type systemd_backlight_exec_t;
init_system_domain(systemd_backlight_t, systemd_backlight_exec_t)
@@ -1462,6 +1458,7 @@ tunable_policy(`systemd_tmpfilesd_factor
')

optional_policy(`
+ dbus_manage_lib_files(systemd_tmpfiles_t)
dbus_read_lib_files(systemd_tmpfiles_t)
dbus_relabel_lib_dirs(systemd_tmpfiles_t)
')
Index: refpolicy-2.20210908/policy/modules/services/cron.te
===================================================================
--- refpolicy-2.20210908.orig/policy/modules/services/cron.te
+++ refpolicy-2.20210908/policy/modules/services/cron.te
@@ -486,6 +486,7 @@ kernel_getattr_core_if(system_cronjob_t)
kernel_getattr_message_if(system_cronjob_t)

kernel_read_crypto_sysctls(system_cronjob_t)
+kernel_read_fs_sysctls(system_cronjob_t)
kernel_read_irq_sysctls(system_cronjob_t)
kernel_read_kernel_sysctls(system_cronjob_t)
kernel_read_network_state(system_cronjob_t)
Index: refpolicy-2.20210908/policy/modules/apps/pulseaudio.te
===================================================================
--- refpolicy-2.20210908.orig/policy/modules/apps/pulseaudio.te
+++ refpolicy-2.20210908/policy/modules/apps/pulseaudio.te
@@ -156,6 +156,7 @@ userdom_search_user_home_content(pulseau
userdom_manage_user_tmp_dirs(pulseaudio_t)
userdom_manage_user_tmp_files(pulseaudio_t)
userdom_manage_user_tmp_sockets(pulseaudio_t)
+userdom_write_all_user_runtime_named_sockets(pulseaudio_t)

tunable_policy(`pulseaudio_execmem',`
allow pulseaudio_t self:process execmem;
Index: refpolicy-2.20210908/policy/modules/services/ntp.te
===================================================================
--- refpolicy-2.20210908.orig/policy/modules/services/ntp.te
+++ refpolicy-2.20210908/policy/modules/services/ntp.te
@@ -130,6 +130,7 @@ term_use_ptmx(ntpd_t)
auth_use_nsswitch(ntpd_t)

init_exec_script_files(ntpd_t)
+init_get_generic_units_status(ntpd_t)

logging_send_syslog_msg(ntpd_t)


2021-10-11 16:12:59

by Daniel Burgener

[permalink] [raw]
Subject: Re: [PATCH] strict policy patches


> ===================================================================
> --- refpolicy-2.20210908.orig/policy/modules/system/systemd.te
> +++ refpolicy-2.20210908/policy/modules/system/systemd.te
> @@ -65,10 +65,6 @@ type systemd_activate_t;
> type systemd_activate_exec_t;
> init_system_domain(systemd_activate_t, systemd_activate_exec_t)
>
> -type systemd_analyze_t;
> -type systemd_analyze_exec_t;
> -init_daemon_domain(systemd_analyze_t, systemd_analyze_exec_t)
> -
> type systemd_backlight_t;
> type systemd_backlight_exec_t;
> init_system_domain(systemd_backlight_t, systemd_backlight_exec_t)

I proposed a similar change last year here and the consensus in the PR
discussion was that it would make more sense to add policy for the
systemd_analyze_t domain for cases that wanted a transition there, but
keeping the general approach of running in the parent domain.

https://github.com/SELinuxProject/refpolicy/pull/321

Of course, no one has actually submitted systemd_analyze_t policy yet,
so maybe the demand for such a use case isn't all that high?

-Daniel

2021-10-11 16:41:33

by Dominick Grift

[permalink] [raw]
Subject: Re: [PATCH] strict policy patches

Daniel Burgener <[email protected]> writes:

>> ===================================================================
>> --- refpolicy-2.20210908.orig/policy/modules/system/systemd.te
>> +++ refpolicy-2.20210908/policy/modules/system/systemd.te
>> @@ -65,10 +65,6 @@ type systemd_activate_t;
>> type systemd_activate_exec_t;
>> init_system_domain(systemd_activate_t, systemd_activate_exec_t)
>> -type systemd_analyze_t;
>> -type systemd_analyze_exec_t;
>> -init_daemon_domain(systemd_analyze_t, systemd_analyze_exec_t)
>> -
>> type systemd_backlight_t;
>> type systemd_backlight_exec_t;
>> init_system_domain(systemd_backlight_t, systemd_backlight_exec_t)
>
> I proposed a similar change last year here and the consensus in the PR
> discussion was that it would make more sense to add policy for the
> systemd_analyze_t domain for cases that wanted a transition there, but
> keeping the general approach of running in the parent domain.
>
> https://github.com/SELinuxProject/refpolicy/pull/321
>
> Of course, no one has actually submitted systemd_analyze_t policy yet,
> so maybe the demand for such a use case isn't all that high?
>
> -Daniel
>

I think I might have argued for keeping it around back then but I do not mind
removing it now. It certainly is not an init_daemon_domain(). One can
always add it later if needed.

--
gpg --locate-keys [email protected]
Key fingerprint = FCD2 3660 5D6B 9D27 7FC6 E0FF DA7E 521F 10F6 4098
Dominick Grift

2021-10-27 21:24:17

by Chris PeBenito

[permalink] [raw]
Subject: Re: [PATCH] strict policy patches

On 10/9/21 06:05, Russell Coker wrote:
> Allow user domains to read kernel sysctls and crypto sysctls.
>
> Add userdom_write_all_user_runtime_named_sockets interface (for pulseaudio_t).
>
> Give sysadm_t more access.
>
> Give dbus domains a little more access.
>
> Allow ssh agent to write to an inherited log file from the X server.
>
> Make systemd_analyze_exec_t an alias for bin_t and remove systemd_analyze_t
> omain.
>
> Allow system cronjobs to read fs sysctls.
>
> Signed-off-by: Russell Coker <[email protected]>

[...]
> Index: refpolicy-2.20210908/policy/modules/roles/sysadm.te
> ===================================================================
> --- refpolicy-2.20210908.orig/policy/modules/roles/sysadm.te
> +++ refpolicy-2.20210908/policy/modules/roles/sysadm.te
> @@ -33,11 +33,22 @@ ifndef(`enable_mls',`
> # Local policy
> #
>
> +allow sysadm_t self:netlink_generic_socket { create setopt bind write read };
> +
> +# for ptrace
> +allow sysadm_t self:netlink_tcpdiag_socket { create write nlmsg_read read };
> +
> +allow sysadm_t self:capability audit_write;
> +allow sysadm_t self:system status;

This seems a bit odd. I would have expected sysadm_systemd_t would be the
target. Was the sysadm systemd --user session running in sysadm_t?


> corecmd_exec_shell(sysadm_t)
>
> corenet_ib_access_unlabeled_pkeys(sysadm_t)
> corenet_ib_manage_subnet_unlabeled_endports(sysadm_t)
>
> +domain_getsched_all_domains(sysadm_t)
> +
> +dev_read_cpuid(sysadm_t)
> dev_read_kmsg(sysadm_t)
>
> logging_watch_all_logs(sysadm_t)
> @@ -58,6 +69,9 @@ init_admin(sysadm_t)
> userdom_manage_user_home_dirs(sysadm_t)
> userdom_home_filetrans_user_home_dir(sysadm_t)
>
> +# for systemd-analyze
> +files_get_etc_unit_status(sysadm_t)
> +
> ifdef(`direct_sysadm_daemon',`
> optional_policy(`
> init_run_daemon(sysadm_t, sysadm_r)
> @@ -1033,6 +1047,10 @@ optional_policy(`
> ')
>
> optional_policy(`
> + systemd_dbus_chat_logind(sysadm_t)
> +')
> +
> +optional_policy(`
> tboot_run_txtstat(sysadm_t, sysadm_r)
> ')
>
> @@ -1100,6 +1118,7 @@ optional_policy(`
> ')
>
> optional_policy(`
> + dev_rw_generic_usb_dev(sysadm_t)

Is this related to usbmodules?

> usbmodules_run(sysadm_t, sysadm_r)
> ')
>
> Index: refpolicy-2.20210908/policy/modules/services/xserver.if
> ===================================================================
> --- refpolicy-2.20210908.orig/policy/modules/services/xserver.if
> +++ refpolicy-2.20210908/policy/modules/services/xserver.if
> @@ -100,6 +100,7 @@ interface(`xserver_restricted_role',`
> xserver_xsession_entry_type($2)
> xserver_dontaudit_write_log($2)
> xserver_stream_connect_xdm($2)
> + xserver_use_user_fonts($2)
> # certain apps want to read xdm.pid file
> xserver_read_xdm_runtime_files($2)
> # gnome-session creates socket under /tmp/.ICE-unix/
> @@ -141,7 +142,7 @@ interface(`xserver_role',`
> gen_require(`
> type iceauth_home_t, xserver_t, xserver_tmp_t, xserver_tmpfs_t, xauth_home_t;
> type user_fonts_t, user_fonts_cache_t, user_fonts_config_t;
> - type mesa_shader_cache_t;
> + type mesa_shader_cache_t, xdm_t;
> ')
>
> xserver_restricted_role($1, $2)
> @@ -184,6 +185,8 @@ interface(`xserver_role',`
>
> xserver_read_xkb_libs($2)
>
> + allow $2 xdm_t:unix_stream_socket accept;

Do you have any context on this? Userdomains don't have read/write xdm_t
unix_stream_socket access, so they wouldn't be able to do anything with it.


> +
> optional_policy(`
> xdg_cache_filetrans($2, mesa_shader_cache_t, dir, "mesa_shader_cache")
> ')
> @@ -1224,6 +1227,7 @@ interface(`xserver_read_xkb_libs',`
> allow $1 xkb_var_lib_t:dir list_dir_perms;
> read_files_pattern($1, xkb_var_lib_t, xkb_var_lib_t)
> read_lnk_files_pattern($1, xkb_var_lib_t, xkb_var_lib_t)
> + allow $1 xkb_var_lib_t:file map;
> ')
>
> ########################################
> Index: refpolicy-2.20210908/policy/modules/services/dbus.if
> ===================================================================
> --- refpolicy-2.20210908.orig/policy/modules/services/dbus.if
> +++ refpolicy-2.20210908/policy/modules/services/dbus.if
> @@ -85,6 +85,7 @@ template(`dbus_role_template',`
>
> allow $3 $1_dbusd_t:unix_stream_socket connectto;
> allow $3 $1_dbusd_t:dbus { send_msg acquire_svc };
> + allow $1_dbusd_t $3:dbus send_msg;
> allow $3 $1_dbusd_t:fd use;
>
> dontaudit $1_dbusd_t self:process getcap;
> @@ -103,9 +104,13 @@ template(`dbus_role_template',`
>
> allow $1_dbusd_t $3:process sigkill;
>
> + allow $1_dbusd_t self:process getcap;
> +
> corecmd_bin_domtrans($1_dbusd_t, $3)
> corecmd_shell_domtrans($1_dbusd_t, $3)
>
> + dev_read_sysfs($1_dbusd_t)
> +
> auth_use_nsswitch($1_dbusd_t)
>
> ifdef(`hide_broken_symptoms',`
> @@ -117,6 +122,15 @@ template(`dbus_role_template',`
> systemd_user_daemon_domain($1, dbusd_exec_t, $1_dbusd_t)
> systemd_user_unix_stream_activated_socket($1_dbusd_t, session_dbusd_runtime_t)
> ')
> +
> + optional_policy(`
> + init_dbus_chat($1_dbusd_t)
> + dbus_system_bus_client($1_dbusd_t)

This opens up bridging the user session busses to the system bus. I don't think
we want this.

> + ')
> +
> + optional_policy(`
> + xdg_read_data_files($1_dbusd_t)
> + ')
> ')


--
Chris PeBenito