From: guido@trentalancia.net (Guido Trentalancia) Date: Fri, 30 Dec 2016 01:36:59 +0100 Subject: [refpolicy] [PATCH v3] xserver: restrict executable memory permissions In-Reply-To: <1482954976.2738.9.camel@trentalancia.net> References: <1482945627.7302.8.camel@trentalancia.net> <1482954976.2738.9.camel@trentalancia.net> Message-ID: <1483058219.31174.0.camel@trentalancia.net> To: refpolicy@oss.tresys.com List-Id: refpolicy.oss.tresys.com The dangerous execheap permission is removed from xdm and the dangerous execmem permission is only enabled for the Gnome Display Manager (gnome-shell running in gdm mode) through a new "gnome_xdm" boolean. This patch also updates the XKB libs file context with their default location, adds the ability to read udev pid files and finally adds a few permissions so that xconsole can run smoothly. Signed-off-by: Guido Trentalancia --- policy/modules/services/xserver.fc | 2 ++ policy/modules/services/xserver.te | 24 +++++++++++++++++++----- 2 files changed, 21 insertions(+), 5 deletions(-) diff -pru a/policy/modules/services/xserver.fc b/policy/modules/services/xserver.fc --- a/policy/modules/services/xserver.fc 2016-12-22 23:12:47.782929703 +0100 +++ b/policy/modules/services/xserver.fc 2016-12-30 01:25:51.383728583 +0100 @@ -79,6 +79,8 @@ HOME_DIR/\.Xauthority.* -- gen_context(s /usr/sbin/lightdm -- gen_context(system_u:object_r:xdm_exec_t,s0) +/usr/share/X11/xkb(/.*)? gen_context(system_u:object_r:xkb_var_lib_t,s0) + /usr/X11R6/bin/[xgkw]dm -- gen_context(system_u:object_r:xdm_exec_t,s0) /usr/X11R6/bin/iceauth -- gen_context(system_u:object_r:iceauth_exec_t,s0) /usr/X11R6/bin/X -- gen_context(system_u:object_r:xserver_exec_t,s0) diff -pru a/policy/modules/services/xserver.te b/policy/modules/services/xserver.te --- a/policy/modules/services/xserver.te 2016-12-22 23:12:47.782929703 +0100 +++ b/policy/modules/services/xserver.te 2016-12-30 01:30:43.634289624 +0100 @@ -42,6 +42,14 @@ gen_tunable(xdm_sysadm_login, false) ## ##

+## Use gnome-shell in gdm mode as the +## X Display Manager (XDM) +##

+## +gen_tunable(gnome_xdm, false) + +## +##

## Support X userspace object manager ##

## @@ -304,6 +312,7 @@ optional_policy(` # allow xdm_t self:capability { setgid setuid sys_resource kill sys_tty_config mknod chown dac_override dac_read_search fowner fsetid ipc_owner sys_nice sys_rawio net_bind_service }; +dontaudit xdm_t self:capability sys_admin; allow xdm_t self:process { setexec setpgid getsched setsched setrlimit signal_perms }; allow xdm_t self:fifo_file rw_fifo_file_perms; allow xdm_t self:shm create_shm_perms; @@ -316,7 +325,7 @@ allow xdm_t self:socket create_socket_pe allow xdm_t self:appletalk_socket create_socket_perms; allow xdm_t self:key { search link write }; -allow xdm_t xconsole_device_t:fifo_file { getattr setattr }; +allow xdm_t xconsole_device_t:fifo_file read_fifo_file_perms; # Allow gdm to run gdm-binary can_exec(xdm_t, xdm_exec_t) @@ -450,6 +459,10 @@ term_setattr_console(xdm_t) term_use_unallocated_ttys(xdm_t) term_setattr_unallocated_ttys(xdm_t) +# for xconsole +term_use_ptmx(xdm_t) +term_use_generic_ptys(xdm_t) + auth_domtrans_pam_console(xdm_t) auth_manage_pam_pid(xdm_t) auth_manage_pam_console_data(xdm_t) @@ -507,6 +520,10 @@ tunable_policy(`xdm_sysadm_login',` # allow xserver_t xdm_tmpfs_t:file rw_file_perms; ') +tunable_policy(`gnome_xdm',` + allow xdm_t self:process execmem; +') + optional_policy(` alsa_domtrans(xdm_t) ') @@ -586,10 +603,6 @@ optional_policy(` optional_policy(` unconfined_domain(xdm_t) unconfined_domtrans(xdm_t) - - ifndef(`distro_redhat',` - allow xdm_t self:process { execheap execmem }; - ') ') optional_policy(` @@ -803,6 +816,7 @@ optional_policy(` optional_policy(` udev_read_db(xserver_t) + udev_read_pid_files(xserver_t) ') optional_policy(`