Mailing List Archive

This adds the nomigrate_t type to the example FLASK policy which allows
domains to be created that dom0 cannot access after building.

Example domain configuration snippet:
seclabel='customer_1:vm_r:nomigrate_t'
init_seclabel='customer_1:vm_r:nomigrate_t_building'

Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
---
docs/misc/xsm-flask.txt | 2 +
tools/flask/policy/policy/modules/xen/xen.if | 56 +++++++++++++++++++++-------
tools/flask/policy/policy/modules/xen/xen.te | 10 +++++
3 files changed, 55 insertions(+), 13 deletions(-)

diff --git a/docs/misc/xsm-flask.txt b/docs/misc/xsm-flask.txt
index 6b0d327..0778a28 100644
--- a/docs/misc/xsm-flask.txt
+++ b/docs/misc/xsm-flask.txt
@@ -60,6 +60,8 @@ that can be used without dom0 disaggregation. The main types for domUs are:
- domU_t is a domain that can communicate with any other domU_t
- isolated_domU_t can only communicate with dom0
- prot_domU_t is a domain type whose creation can be disabled with a boolean
+ - nomigrate_t is a domain that must be created via the nomigrate_t_building
+ type, and whose memory cannot be read by dom0 once created

HVM domains with stubdomain device models use two types (one per domain):
- domHVM_t is an HVM domain that uses a stubdomain device model
diff --git a/tools/flask/policy/policy/modules/xen/xen.if b/tools/flask/policy/policy/modules/xen/xen.if
index 3f58909..2ad11b2 100644
--- a/tools/flask/policy/policy/modules/xen/xen.if
+++ b/tools/flask/policy/policy/modules/xen/xen.if
@@ -9,24 +9,47 @@
# Declare a type as a domain type, and allow basic domain setup
define(`declare_domain', `
type $1, domain_type`'ifelse(`$#', `1', `', `,shift($@)');
+ type $1_channel, event_type;
+ type_transition $1 domain_type:event $1_channel;
allow $1 $1:grant { query setup };
allow $1 $1:mmu { adjust physmap map_read map_write stat pinpage };
allow $1 $1:hvm { getparam setparam };
')

-# create_domain(priv, target)
-# Allow a domain to be created
-define(`create_domain', `
+# declare_build_label(type)
+# Declare a paired _building type for the given domain type
+define(`declare_build_label', `
+ type $1_building, domain_type;
+ type_transition $1_building domain_type:event $1_channel;
+ allow $1_building $1 : domain transition;
+')
+
+define(`create_domain_common', `
allow $1 $2:domain { create max_vcpus setdomainmaxmem setaddrsize
- getdomaininfo hypercall setvcpucontext scheduler
- unpause getvcpuinfo getvcpuextstate getaddrsize
- getvcpuaffinity };
+ getdomaininfo hypercall setvcpucontext setextvcpucontext
+ scheduler getvcpuinfo getvcpuextstate getaddrsize
+ getvcpuaffinity setvcpuaffinity };
allow $1 $2:security check_context;
allow $1 $2:shadow enable;
allow $1 $2:mmu {map_read map_write adjust memorymap physmap pinpage};
allow $1 $2:grant setup;
- allow $1 $2:hvm { cacheattr getparam hvmctl irqlevel pciroute setparam pcilevel trackdirtyvram };
- allow $1 $2_$1_channel:event create;
+ allow $1 $2:hvm { cacheattr getparam hvmctl irqlevel pciroute sethvmc setparam pcilevel trackdirtyvram };
+')
+
+# create_domain(priv, target)
+# Allow a domain to be created directly
+define(`create_domain', `
+ create_domain_common($1, $2)
+ allow $1 $2_channel:event create;
+')
+
+# create_domain_build_label(priv, target)
+# Allow a domain to be created via its domain build label
+define(`create_domain_build_label', `
+ create_domain_common($1, $2_building)
+ allow $1 $2_channel:event create;
+ allow $1 $2_building:domain2 relabelfrom;
+ allow $1 $2:domain2 relabelto;
')

# manage_domain(priv, target)
@@ -37,6 +60,15 @@ define(`manage_domain', `
setvcpuaffinity setdomainmaxmem };
')

+# migrate_domain_out(priv, target)
+# Allow creation of a snapshot or migration image from a domain
+# (inbound migration is the same as domain creation)
+define(`migrate_domain_out', `
+ allow $1 $2:hvm { gethvmc getparam irqlevel };
+ allow $1 $2:mmu { stat pageinfo map_read };
+ allow $1 $2:domain { getaddrsize getvcpucontext getextvcpucontext getvcpuextstate pause destroy };
+')
+
################################################################################
#
# Inter-domain communication
@@ -47,8 +79,6 @@ define(`manage_domain', `
# This allows an event channel to be created from domains with labels
# <source> to <dest> and will label it <chan-label>
define(`create_channel', `
- type $3, event_type;
- type_transition $1 $2:event $3;
allow $1 $3:event { create send status };
allow $3 $2:event { bind };
')
@@ -56,8 +86,8 @@ define(`create_channel', `
# domain_event_comms(dom1, dom2)
# Allow two domain types to communicate using event channels
define(`domain_event_comms', `
- create_channel($1, $2, $1_$2_channel)
- create_channel($2, $1, $2_$1_channel)
+ create_channel($1, $2, $1_channel)
+ create_channel($2, $1, $2_channel)
')

# domain_comms(dom1, dom2)
@@ -72,7 +102,7 @@ define(`domain_comms', `
# Allow a domain types to communicate with others of its type using grants
# and event channels (this includes event channels to DOMID_SELF)
define(`domain_self_comms', `
- create_channel($1, $1, $1_self_channel)
+ create_channel($1, $1, $1_channel)
allow $1 $1:grant { map_read map_write copy unmap };
')

diff --git a/tools/flask/policy/policy/modules/xen/xen.te b/tools/flask/policy/policy/modules/xen/xen.te
index 9550397..1162153 100644
--- a/tools/flask/policy/policy/modules/xen/xen.te
+++ b/tools/flask/policy/policy/modules/xen/xen.te
@@ -90,6 +90,7 @@ create_domain(dom0_t, isolated_domU_t)
manage_domain(dom0_t, isolated_domU_t)
domain_comms(dom0_t, isolated_domU_t)

+# Declare a boolean that denies creation of prot_domU_t domains
gen_bool(prot_doms_locked, false)
declare_domain(prot_domU_t)
if (!prot_doms_locked) {
@@ -111,6 +112,15 @@ manage_domain(dom0_t, dm_dom_t)
domain_comms(dom0_t, dm_dom_t)
device_model(dm_dom_t, domHVM_t)

+# nomigrate_t must be built via the nomigrate_t_building label; once built,
+# dom0 cannot read its memory.
+declare_domain(nomigrate_t)
+declare_build_label(nomigrate_t)
+create_domain_build_label(dom0_t, nomigrate_t)
+manage_domain(dom0_t, nomigrate_t)
+domain_comms(dom0_t, nomigrate_t)
+domain_self_comms(nomigrate_t)
+
###############################################################################
#
# Device delegation
--
1.7.11.7


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