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|
Author: Sebastian Reichel <sebastian.reichel@collabora.com>
Description: add apparmor support
Forwarded: https://github.com/bus1/dbus-broker/pull/286
--- a/src/bus/policy.c
+++ b/src/bus/policy.c
@@ -1064,7 +1064,7 @@
size_t i;
int r;
- r = bus_apparmor_check_xmit(snapshot->apparmor, true, snapshot->seclabel, subject_seclabel,
+ r = bus_apparmor_check_send(snapshot->apparmor, snapshot->seclabel, subject_seclabel,
subject, subject_id, path, interface, method);
if (r) {
if (r == BUS_APPARMOR_E_DENIED)
@@ -1111,16 +1111,6 @@
size_t n_fds) {
PolicyVerdict verdict = POLICY_VERDICT_INIT;
size_t i;
- int r;
-
- r = bus_apparmor_check_xmit(snapshot->apparmor, false, subject_seclabel, snapshot->seclabel,
- subject, subject_id, path, interface, method);
- if (r) {
- if (r == BUS_APPARMOR_E_DENIED)
- return POLICY_E_APPARMOR_ACCESS_DENIED;
-
- return error_fold(r);
- }
for (i = 0; i < snapshot->n_batches; ++i)
policy_snapshot_check_xmit(snapshot->batches[i],
--- a/src/util/apparmor-fallback.c
+++ b/src/util/apparmor-fallback.c
@@ -62,7 +62,7 @@
return 0;
}
-int bus_apparmor_check_xmit(BusAppArmorRegistry *registry, bool check_send,
+int bus_apparmor_check_send(BusAppArmorRegistry *registry,
const char *sender_context, const char *receiver_context,
NameSet *subject, uint64_t subject_id,
const char *path, const char *interface, const char *method) {
--- a/src/util/apparmor.c
+++ b/src/util/apparmor.c
@@ -473,26 +473,25 @@
if (r)
return error_origin(-c_errno());
+ if (string_equal(security_mode, "complain"))
+ allow = true;
+
if (audit)
bus_apparmor_log(
registry,
"apparmor=\"%s\" operation=\"dbus_bind\" "
- "bus=\"%s\" name=\"%s\"",
+ "bus=\"%s\" name=\"%s\" mask=\"bind\"",
allow ? "ALLOWED" : "DENIED",
registry->bustype,
name
);
- if (string_equal(security_mode, "complain"))
- allow = true;
-
return allow ? 0 : BUS_APPARMOR_E_DENIED;
}
/**
- * bus_apparmor_check_xmit() - check if the given transaction is allowed
+ * bus_apparmor_check_send() - check if the given transaction is allowed
* @registry: AppArmor registry to operate on
- * @check_send: true if sending should be checked, false if receiving
* @sender_context: security context of the sender
* @receiver_context: security context of the receiver, or NULL
* @subject: List of names
@@ -511,8 +510,7 @@
* Return: 0 if the transaction is allowed, BUS_APPARMOR_E_DENIED if it is not,
* or a negative error code on failure.
*/
-int bus_apparmor_check_xmit(BusAppArmorRegistry *registry,
- bool check_send,
+int bus_apparmor_check_send(BusAppArmorRegistry *registry,
const char *sender_context,
const char *receiver_context,
NameSet *subject,
@@ -524,7 +522,7 @@
_c_cleanup_(c_freep) char *receiver_context_dup = NULL;
char *sender_security_label, *sender_security_mode;
char *receiver_security_label, *receiver_security_mode;
- int r, allow, audit;
+ int r, src_allow = false, src_audit = true, dst_allow = false, dst_audit = true;
if (!registry->bustype)
return 0;
@@ -539,46 +537,71 @@
sender_security_label = aa_splitcon(sender_context_dup, &sender_security_mode);
receiver_security_label = aa_splitcon(receiver_context_dup, &receiver_security_mode);
- if (is_unconfined(sender_security_label, sender_security_mode))
- return 0;
- if (is_unconfined(receiver_security_label, receiver_security_mode))
- return 0;
-
- if (check_send)
+ if (is_unconfined(sender_security_label, sender_security_mode)) {
+ src_allow = true;
+ src_audit = false;
+ } else {
r = apparmor_message_query(true,
sender_security_label,
registry->bustype,
receiver_security_label,
subject, subject_id, path,
- interface, method, &allow, &audit);
- else
+ interface, method, &src_allow, &src_audit);
+
+ if (r)
+ return error_fold(r);
+ }
+
+ if (is_unconfined(receiver_security_label, receiver_security_mode)) {
+ dst_allow = true;
+ dst_audit = false;
+ } else {
r = apparmor_message_query(false,
receiver_security_label,
registry->bustype,
sender_security_label,
subject, subject_id, path,
- interface, method, &allow, &audit);
- if (r)
- return error_fold(r);
-
- if (audit)
- bus_apparmor_log(
- registry,
- "apparmor=\"%s\" operation=\"dbus_%s\" bus=\"%s\" "
- "path=\"%s\" interface=\"%s\" method=\"%s\"",
- allow ? "ALLOWED" : "DENIED",
- check_send ? "send" : "receive",
+ interface, method, &dst_allow, &dst_audit);
+ if (r)
+ return error_fold(r);
+ }
+
+ if (string_equal(sender_security_mode, "complain"))
+ src_allow = 1;
+ if (string_equal(receiver_security_mode, "complain"))
+ dst_allow = 1;
+
+ if (src_audit) {
+ bus_apparmor_log(registry,
+ "apparmor=\"%s\" operation=\"dbus_method_call\" "
+ "bus=\"%s\" path=\"%s\" interface=\"%s\" method=\"%s\" "
+ "mask=\"send\" label=\"%s\" peer_label=\"%s\"",
+ src_allow ? "ALLOWED" : "DENIED",
registry->bustype,
path,
interface,
- method
+ method,
+ sender_security_label,
+ receiver_security_label
);
+ }
- if ((check_send && string_equal(sender_security_mode, "complain")) ||
- (!check_send && string_equal(receiver_security_mode, "complain")))
- allow = 1;
+ if (dst_audit) {
+ bus_apparmor_log(registry,
+ "apparmor=\"%s\" operation=\"dbus_method_call\" "
+ "bus=\"%s\" path=\"%s\" interface=\"%s\" method=\"%s\" "
+ "mask=\"receive\" label=\"%s\" peer_label=\"%s\"",
+ dst_allow ? "ALLOWED" : "DENIED",
+ registry->bustype,
+ path,
+ interface,
+ method,
+ receiver_security_label,
+ sender_security_label
+ );
+ }
- return allow ? 0 : BUS_APPARMOR_E_DENIED;
+ return (src_allow && dst_allow) ? 0 : BUS_APPARMOR_E_DENIED;
}
/**
@@ -624,6 +647,9 @@
if (r)
return error_origin(-c_errno());
+ if (string_equal(security_mode, "complain"))
+ allow = 1;
+
if (audit)
bus_apparmor_log(
registry,
@@ -634,8 +660,5 @@
context
);
- if (string_equal(security_mode, "complain"))
- allow = 1;
-
return allow ? 0 : BUS_APPARMOR_E_DENIED;
}
--- a/src/util/apparmor.h
+++ b/src/util/apparmor.h
@@ -29,7 +29,7 @@
int bus_apparmor_check_own(struct BusAppArmorRegistry *registry, const char *context,
const char *name);
-int bus_apparmor_check_xmit(BusAppArmorRegistry *registry, bool check_send,
+int bus_apparmor_check_send(BusAppArmorRegistry *registry,
const char *sender_context, const char *receiver_context,
NameSet *subject, uint64_t subject_id,
const char *path, const char *interface, const char *method);
--- a/src/launch/launcher.c
+++ b/src/launch/launcher.c
@@ -1156,6 +1156,55 @@
return 0;
}
+/**
+ * launcher_apparmor_check() - checks if AppArmor should be used
+ * @apparmor_mode: bi-directional argument telling if AppArmor should be enabled
+ *
+ * This should be called with the requested apparmor mode. The
+ * function modifies the mode to either CONFIG_APPARMOR_DISABLED
+ * or CONFIG_APPARMOR_ENABLED based on platform support. If the
+ * function keeps the mode as CONFIG_APPARMOR_REQUIRED, AppArmor
+ * has been configured as mandatory but is not supported.
+ *
+ * Returns: 0 if check succeeded, or negative error code on failure.
+ */
+int launcher_apparmor_check(unsigned int *apparmor_mode) {
+ bool enabled, supported;
+ int r;
+
+ if (*apparmor_mode == CONFIG_APPARMOR_DISABLED)
+ return CONFIG_APPARMOR_DISABLED;
+
+ r = bus_apparmor_is_enabled(&enabled);
+ if (r)
+ return error_fold(r);
+
+ r = bus_apparmor_dbus_supported(&supported);
+ if (r)
+ return error_fold(r);
+
+ if (*apparmor_mode == CONFIG_APPARMOR_ENABLED) {
+ if (enabled && !supported) {
+ fprintf(stderr, "Kernel is missing AppArmor DBus support.\n");
+ *apparmor_mode = CONFIG_APPARMOR_DISABLED;
+ } else if (enabled) {
+ *apparmor_mode = CONFIG_APPARMOR_ENABLED;
+ } else {
+ *apparmor_mode = CONFIG_APPARMOR_DISABLED;
+ }
+ } else if (*apparmor_mode == CONFIG_APPARMOR_REQUIRED) {
+ if (!enabled || !supported) {
+ fprintf(stderr, "AppArmor required, but not supported. Exiting.\n");
+ *apparmor_mode = CONFIG_APPARMOR_REQUIRED;
+ } else {
+ *apparmor_mode = CONFIG_APPARMOR_ENABLED;
+ }
+ }
+
+ return 0;
+}
+
+
static int launcher_reload_config(Launcher *launcher) {
_c_cleanup_(config_root_freep) ConfigRoot *root = NULL;
_c_cleanup_(policy_deinit) Policy policy = POLICY_INIT(policy);
@@ -1196,29 +1245,13 @@
if (r)
goto out;
- switch (policy.apparmor_mode) {
- case CONFIG_APPARMOR_ENABLED: {
- bool enabled;
-
- /* XXX: See comments in launcher_run() */
-
- r = bus_apparmor_is_enabled(&enabled);
- if (r)
- return error_fold(r);
-
- if (enabled)
- fprintf(stderr, "AppArmor enabled, but not supported. Ignoring.\n");
-
- policy.apparmor_mode = CONFIG_APPARMOR_DISABLED;
- break;
- }
- case CONFIG_APPARMOR_REQUIRED:
- fprintf(stderr, "AppArmor required, but not supported. Exiting.\n");
-
+ r = launcher_apparmor_check(&policy.apparmor_mode);
+ if (r < 0)
+ return error_fold(r);
+ if (policy.apparmor_mode == CONFIG_APPARMOR_REQUIRED) {
r = sd_event_exit(launcher->event, 0);
if (r < 0)
return error_fold(r);
-
return 0;
}
@@ -1348,35 +1381,11 @@
if (r)
return error_trace(r);
- switch (policy.apparmor_mode) {
- case CONFIG_APPARMOR_ENABLED: {
- bool enabled, supported;
-
- r = bus_apparmor_is_enabled(&enabled);
- if (r)
- return error_fold(r);
-
- r = bus_apparmor_dbus_supported(&supported);
- if (r)
- return error_fold(r);
-
- if (enabled && !supported)
- fprintf(stderr, "Kernel is missing AppArmor DBus support. Ignoring.\n");
- else if (enabled)
- fprintf(stderr, "AppArmor enabled, but not supported. Ignoring.\n");
-
- /* XXX: once the broker supports AppArmor, set this to DISABLED if and only if
- * it is disabled in the kernel. */
- policy.apparmor_mode = CONFIG_APPARMOR_DISABLED;
- break;
- }
- case CONFIG_APPARMOR_REQUIRED:
- fprintf(stderr, "AppArmor required, but not supported. Exiting.\n");
-
- /* XXX: once the broker supports AppArmor, set this to enabled if and only
- * if it is enabled in the kernel, and exit the launcher otherwise. */
+ r = launcher_apparmor_check(&policy.apparmor_mode);
+ if (r < 0)
+ return error_fold(r);
+ if (policy.apparmor_mode == CONFIG_APPARMOR_REQUIRED)
return 0;
- }
c_assert(launcher->fd_listen >= 0);
|
