[PATCH testsuite] lockdown: use debugfs/tracefs to test lockdown permissions

[Ondrej Mosnacek <omosnace@redhat.com>]

The system policy interfaces for things that require lockdown
permissions will likely grant those permissions, too, so we need to
open-code them. Thus, use tracefs/debugfs access to test lockdown, as
the interfaces for these are easier to open-code.

With this patch, the lockdown test passes with latest Fedora policy in
Rawhide.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
---
 defconfig               |  5 +++++
 policy/test_lockdown.te | 16 ++++++++--------
 policy/test_policy.if   | 17 +++++++++++++++++
 tests/lockdown/test     | 21 +++++++++++++--------
 4 files changed, 43 insertions(+), 16 deletions(-)

diff --git a/defconfig b/defconfig
index 46eb673..ca7a877 100644
--- a/defconfig
+++ b/defconfig
@@ -117,3 +117,8 @@ CONFIG_VFAT_FS=m
 # They are not required for SELinux operation itself.
 CONFIG_WATCH_QUEUE=y
 CONFIG_KEY_NOTIFICATIONS=y
+
+# Test lockdown permissions (via tracefs and debugfs).
+# This is not required for SELinux operation itself.
+CONFIG_TRACING=y
+CONFIG_DEBUG_FS=y
diff --git a/policy/test_lockdown.te b/policy/test_lockdown.te
index a7a4b6b..1ec985e 100644
--- a/policy/test_lockdown.te
+++ b/policy/test_lockdown.te
@@ -12,8 +12,8 @@ unconfined_runs_test(test_lockdown_all_t)
 typeattribute test_lockdown_all_t lockdowndomain;
 typeattribute test_lockdown_all_t testdomain;
 
-dev_read_raw_memory(test_lockdown_all_t)
-kernel_read_core_if(test_lockdown_all_t)
+testsuite_read_debugfs_nolockdown(test_lockdown_all_t)
+testsuite_read_tracefs_nolockdown(test_lockdown_all_t)
 corecmd_bin_entry_type(test_lockdown_all_t)
 allow test_lockdown_all_t self:lockdown integrity;
 allow test_lockdown_all_t self:lockdown confidentiality;
@@ -25,8 +25,8 @@ unconfined_runs_test(test_lockdown_integrity_t)
 typeattribute test_lockdown_integrity_t lockdowndomain;
 typeattribute test_lockdown_integrity_t testdomain;
 
-dev_read_raw_memory(test_lockdown_integrity_t)
-kernel_read_core_if(test_lockdown_integrity_t)
+testsuite_read_debugfs_nolockdown(test_lockdown_integrity_t)
+testsuite_read_tracefs_nolockdown(test_lockdown_integrity_t)
 corecmd_bin_entry_type(test_lockdown_integrity_t)
 allow test_lockdown_integrity_t self:lockdown integrity;
 
@@ -37,8 +37,8 @@ unconfined_runs_test(test_lockdown_confidentiality_t)
 typeattribute test_lockdown_confidentiality_t lockdowndomain;
 typeattribute test_lockdown_confidentiality_t testdomain;
 
-dev_read_raw_memory(test_lockdown_confidentiality_t)
-kernel_read_core_if(test_lockdown_confidentiality_t)
+testsuite_read_debugfs_nolockdown(test_lockdown_confidentiality_t)
+testsuite_read_tracefs_nolockdown(test_lockdown_confidentiality_t)
 corecmd_bin_entry_type(test_lockdown_confidentiality_t)
 allow test_lockdown_confidentiality_t self:lockdown confidentiality;
 
@@ -49,6 +49,6 @@ unconfined_runs_test(test_lockdown_none_t)
 typeattribute test_lockdown_none_t lockdowndomain;
 typeattribute test_lockdown_none_t testdomain;
 
-dev_read_raw_memory(test_lockdown_none_t)
-kernel_read_core_if(test_lockdown_none_t)
+testsuite_read_debugfs_nolockdown(test_lockdown_none_t)
+testsuite_read_tracefs_nolockdown(test_lockdown_none_t)
 corecmd_bin_entry_type(test_lockdown_none_t)
diff --git a/policy/test_policy.if b/policy/test_policy.if
index e3c01c8..7023e30 100644
--- a/policy/test_policy.if
+++ b/policy/test_policy.if
@@ -87,3 +87,20 @@ interface(`userdom_search_admin_dir', `
 ifdef(`kernel_request_load_module', `', ` dnl
 interface(`kernel_request_load_module', `')
 ')
+
+# We need to open-code these interfaces, because the system-provided ones will
+# likely grant the lockdown permissions we want to test.
+interface(`testsuite_read_debugfs_nolockdown',`
+	gen_require(`
+		type debugfs_t;
+	')
+
+	read_files_pattern($1, debugfs_t, debugfs_t)
+')
+interface(`testsuite_read_tracefs_nolockdown',`
+	gen_require(`
+		type tracefs_t;
+	')
+
+	read_files_pattern($1, tracefs_t, tracefs_t)
+')
diff --git a/tests/lockdown/test b/tests/lockdown/test
index 0b81cb1..6694a4c 100755
--- a/tests/lockdown/test
+++ b/tests/lockdown/test
@@ -3,40 +3,45 @@
 use Test;
 BEGIN { plan tests => 8 }
 
+$integrity_cmd       = "head -c 1 /sys/kernel/debug/sched_features";
+$confidentiality_cmd = "head -c 1 /sys/kernel/debug/tracing/tracing_on";
+
 # everything is allowed
 $result =
-  system "runcon -t test_lockdown_all_t -- head /dev/mem > /dev/null 2>&1";
+  system "runcon -t test_lockdown_all_t -- $integrity_cmd > /dev/null 2>&1";
 ok( $result, 0 );
 
 $result =
-  system "runcon -t test_lockdown_all_t -- head /proc/kcore > /dev/null 2>&1";
+  system
+  "runcon -t test_lockdown_all_t -- $confidentiality_cmd > /dev/null 2>&1";
 ok( $result, 0 );
 
 # only integrity operations allowed
 $result = system
-  "runcon -t test_lockdown_integrity_t -- head /dev/mem > /dev/null 2>&1";
+  "runcon -t test_lockdown_integrity_t -- $integrity_cmd > /dev/null 2>&1";
 ok( $result, 0 );
 
 $result = system
-  "runcon -t test_lockdown_integrity_t -- head /proc/kcore > /dev/null 2>&1";
+"runcon -t test_lockdown_integrity_t -- $confidentiality_cmd > /dev/null 2>&1";
 ok($result);
 
 # only confidentiality operations allowed
 $result = system
-  "runcon -t test_lockdown_confidentiality_t -- head /dev/mem > /dev/null 2>&1";
+"runcon -t test_lockdown_confidentiality_t -- $integrity_cmd > /dev/null 2>&1";
 ok($result);
 
 $result = system
-"runcon -t test_lockdown_confidentiality_t -- head /proc/kcore > /dev/null 2>&1";
+"runcon -t test_lockdown_confidentiality_t -- $confidentiality_cmd > /dev/null 2>&1";
 ok( $result, 0 );
 
 # nothing is allowed
 $result =
-  system "runcon -t test_lockdown_none_t -- head /dev/mem > /dev/null 2>&1";
+  system "runcon -t test_lockdown_none_t -- $integrity_cmd > /dev/null 2>&1";
 ok($result);
 
 $result =
-  system "runcon -t test_lockdown_none_t -- head /proc/kcore > /dev/null 2>&1";
+  system
+  "runcon -t test_lockdown_none_t -- $confidentiality_cmd > /dev/null 2>&1";
 ok($result);
 
 exit;
-- 
2.29.2