2021-10-09 09:59:38

by Russell Coker

[permalink] [raw]
Subject: [PATCH] patch for sddm with PAM

This patch makes the recent versions of sddm work for X logins. Sddm uses
PAM to start the actual XDM under a different UID so we have to work with
this.

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

Index: refpolicy-2.20210908/policy/modules/services/xserver.te
===================================================================
--- refpolicy-2.20210908.orig/policy/modules/services/xserver.te
+++ refpolicy-2.20210908/policy/modules/services/xserver.te
@@ -18,6 +18,7 @@ gen_require(`
class x_resource all_x_resource_perms;
class x_event all_x_event_perms;
class x_synthetic_event all_x_synthetic_event_perms;
+ role xdm_r;
')

########################################
@@ -152,6 +153,10 @@ init_daemon_domain(xdm_t, xdm_exec_t)
xserver_object_types_template(xdm)
xserver_common_x_domain_template(xdm, xdm_t)

+# for sddm to use pam for greeter
+role xdm_r types xdm_t;
+allow system_r xdm_r;
+
type xdm_lock_t;
files_lock_file(xdm_lock_t)

@@ -848,6 +853,9 @@ manage_files_pattern(xserver_t, xdm_tmp_
manage_lnk_files_pattern(xserver_t, xdm_tmp_t, xdm_tmp_t)
manage_sock_files_pattern(xserver_t, xdm_tmp_t, xdm_tmp_t)

+# for sddm to use pam for greeter, sddm greeter needs execmod
+allow xdm_t xdm_tmpfs_t:file execmod;
+
# Run Xorg.wrap
can_exec(xserver_t, xserver_exec_t)

Index: refpolicy-2.20210908/config/appconfig-mcs/seusers
===================================================================
--- refpolicy-2.20210908.orig/config/appconfig-mcs/seusers
+++ refpolicy-2.20210908/config/appconfig-mcs/seusers
@@ -1,2 +1,3 @@
root:unconfined_u:s0-mcs_systemhigh
__default__:unconfined_u:s0-mcs_systemhigh
+sddm:xdm:s0
Index: refpolicy-2.20210908/policy/users
===================================================================
--- refpolicy-2.20210908.orig/policy/users
+++ refpolicy-2.20210908/policy/users
@@ -27,6 +27,7 @@ gen_user(system_u,, system_r, s0, s0 - m
gen_user(user_u, user, user_r, s0, s0)
gen_user(staff_u, staff, staff_r sysadm_r ifdef(`enable_mls',`secadm_r auditadm_r'), s0, s0 - mls_systemhigh, mcs_allcats)
gen_user(sysadm_u, sysadm, sysadm_r, s0, s0 - mls_systemhigh, mcs_allcats)
+gen_user(xdm, user, xdm_r, s0, s0)

# Until order dependence is fixed for users:
ifdef(`direct_sysadm_daemon',`
Index: refpolicy-2.20210908/config/appconfig-mcs/xdm_default_contexts
===================================================================
--- /dev/null
+++ refpolicy-2.20210908/config/appconfig-mcs/xdm_default_contexts
@@ -0,0 +1 @@
+system_r:xdm_t:s0 xdm_r:xdm_t:s0
Index: refpolicy-2.20210908/policy/modules/kernel/kernel.te
===================================================================
--- refpolicy-2.20210908.orig/policy/modules/kernel/kernel.te
+++ refpolicy-2.20210908/policy/modules/kernel/kernel.te
@@ -32,6 +32,7 @@ role system_r;
role sysadm_r;
role staff_r;
role user_r;
+role xdm_r;

# here until order dependence is fixed:
role unconfined_r;


2021-10-27 21:24:12

by Chris PeBenito

[permalink] [raw]
Subject: Re: [PATCH] patch for sddm with PAM

On 10/9/21 05:52, Russell Coker wrote:
> This patch makes the recent versions of sddm work for X logins. Sddm uses
> PAM to start the actual XDM under a different UID so we have to work with
> this.
>
> Signed-off-by: Russell Coker <[email protected]>
>
> Index: refpolicy-2.20210908/policy/modules/services/xserver.te
> ===================================================================
> --- refpolicy-2.20210908.orig/policy/modules/services/xserver.te
> +++ refpolicy-2.20210908/policy/modules/services/xserver.te
> @@ -18,6 +18,7 @@ gen_require(`
> class x_resource all_x_resource_perms;
> class x_event all_x_event_perms;
> class x_synthetic_event all_x_synthetic_event_perms;
> + role xdm_r;
> ')
>
> ########################################
> @@ -152,6 +153,10 @@ init_daemon_domain(xdm_t, xdm_exec_t)
> xserver_object_types_template(xdm)
> xserver_common_x_domain_template(xdm, xdm_t)
>
> +# for sddm to use pam for greeter
> +role xdm_r types xdm_t;
> +allow system_r xdm_r;
> +
> type xdm_lock_t;
> files_lock_file(xdm_lock_t)
>
> @@ -848,6 +853,9 @@ manage_files_pattern(xserver_t, xdm_tmp_
> manage_lnk_files_pattern(xserver_t, xdm_tmp_t, xdm_tmp_t)
> manage_sock_files_pattern(xserver_t, xdm_tmp_t, xdm_tmp_t)
>
> +# for sddm to use pam for greeter, sddm greeter needs execmod
> +allow xdm_t xdm_tmpfs_t:file execmod;
> +
> # Run Xorg.wrap
> can_exec(xserver_t, xserver_exec_t)
>
> Index: refpolicy-2.20210908/config/appconfig-mcs/seusers
> ===================================================================
> --- refpolicy-2.20210908.orig/config/appconfig-mcs/seusers
> +++ refpolicy-2.20210908/config/appconfig-mcs/seusers
> @@ -1,2 +1,3 @@
> root:unconfined_u:s0-mcs_systemhigh
> __default__:unconfined_u:s0-mcs_systemhigh
> +sddm:xdm:s0
> Index: refpolicy-2.20210908/policy/users
> ===================================================================
> --- refpolicy-2.20210908.orig/policy/users
> +++ refpolicy-2.20210908/policy/users
> @@ -27,6 +27,7 @@ gen_user(system_u,, system_r, s0, s0 - m
> gen_user(user_u, user, user_r, s0, s0)
> gen_user(staff_u, staff, staff_r sysadm_r ifdef(`enable_mls',`secadm_r auditadm_r'), s0, s0 - mls_systemhigh, mcs_allcats)
> gen_user(sysadm_u, sysadm, sysadm_r, s0, s0 - mls_systemhigh, mcs_allcats)
> +gen_user(xdm, user, xdm_r, s0, s0)
>
> # Until order dependence is fixed for users:
> ifdef(`direct_sysadm_daemon',`
> Index: refpolicy-2.20210908/config/appconfig-mcs/xdm_default_contexts
> ===================================================================
> --- /dev/null
> +++ refpolicy-2.20210908/config/appconfig-mcs/xdm_default_contexts
> @@ -0,0 +1 @@
> +system_r:xdm_t:s0 xdm_r:xdm_t:s0
> Index: refpolicy-2.20210908/policy/modules/kernel/kernel.te
> ===================================================================
> --- refpolicy-2.20210908.orig/policy/modules/kernel/kernel.te
> +++ refpolicy-2.20210908/policy/modules/kernel/kernel.te
> @@ -32,6 +32,7 @@ role system_r;
> role sysadm_r;
> role staff_r;
> role user_r;
> +role xdm_r;
>
> # here until order dependence is fixed:
> role unconfined_r;

I'm confused by this. There is a login that happens prior to SDDM starting?
There also is no role change allowed from xdm_r to the user role.


--
Chris PeBenito