From: pebenito@ieee.org (Chris PeBenito) Date: Fri, 30 Dec 2016 14:32:40 -0500 Subject: [refpolicy] [PATCH v3] xserver: restrict executable memory permissions In-Reply-To: <1483058219.31174.0.camel@trentalancia.net> References: <1482945627.7302.8.camel@trentalancia.net> <1482954976.2738.9.camel@trentalancia.net> <1483058219.31174.0.camel@trentalancia.net> Message-ID: To: refpolicy@oss.tresys.com List-Id: refpolicy.oss.tresys.com On 12/29/16 19:36, Guido Trentalancia via refpolicy wrote: > 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) The tunable name should start with xserver. > +## > +##

> ## 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; The setattr permission is lost. > # 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) Looks like a pty needs to be properly labeled. > 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(` -- Chris PeBenito