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-rw-r--r--tools/testing/selftests/kdbus/test-policy-priv.c1285
1 files changed, 1285 insertions, 0 deletions
diff --git a/tools/testing/selftests/kdbus/test-policy-priv.c b/tools/testing/selftests/kdbus/test-policy-priv.c
new file mode 100644
index 000000000000..0208638a7245
--- /dev/null
+++ b/tools/testing/selftests/kdbus/test-policy-priv.c
@@ -0,0 +1,1285 @@
+#include <errno.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <time.h>
+#include <sys/capability.h>
+#include <sys/eventfd.h>
+#include <sys/wait.h>
+
+#include "kdbus-test.h"
+#include "kdbus-util.h"
+#include "kdbus-enum.h"
+
+static int test_policy_priv_by_id(const char *bus,
+ struct kdbus_conn *conn_dst,
+ bool drop_second_user,
+ int parent_status,
+ int child_status)
+{
+ int ret = 0;
+ uint64_t expected_cookie = time(NULL) ^ 0xdeadbeef;
+
+ ASSERT_RETURN(conn_dst);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, bus, ({
+ ret = kdbus_msg_send(unpriv, NULL,
+ expected_cookie, 0, 0, 0,
+ conn_dst->id);
+ ASSERT_EXIT(ret == child_status);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ ret = kdbus_msg_recv_poll(conn_dst, 300, NULL, NULL);
+ ASSERT_RETURN(ret == parent_status);
+
+ return 0;
+}
+
+static int test_policy_priv_by_broadcast(const char *bus,
+ struct kdbus_conn *conn_dst,
+ int drop_second_user,
+ int parent_status,
+ int child_status)
+{
+ int efd;
+ int ret = 0;
+ eventfd_t event_status = 0;
+ struct kdbus_msg *msg = NULL;
+ uid_t second_uid = UNPRIV_UID;
+ gid_t second_gid = UNPRIV_GID;
+ struct kdbus_conn *child_2 = conn_dst;
+ uint64_t expected_cookie = time(NULL) ^ 0xdeadbeef;
+
+ /* Drop to another unprivileged user other than UNPRIV_UID */
+ if (drop_second_user == DROP_OTHER_UNPRIV) {
+ second_uid = UNPRIV_UID - 1;
+ second_gid = UNPRIV_GID - 1;
+ }
+
+ /* child will signal parent to send broadcast */
+ efd = eventfd(0, EFD_CLOEXEC);
+ ASSERT_RETURN_VAL(efd >= 0, efd);
+
+ ret = RUN_UNPRIVILEGED(UNPRIV_UID, UNPRIV_GID, ({
+ struct kdbus_conn *child;
+
+ child = kdbus_hello(bus, 0, NULL, 0);
+ ASSERT_EXIT(child);
+
+ ret = kdbus_add_match_empty(child);
+ ASSERT_EXIT(ret == 0);
+
+ /* signal parent */
+ ret = eventfd_write(efd, 1);
+ ASSERT_EXIT(ret == 0);
+
+ /* Use a little bit high time */
+ ret = kdbus_msg_recv_poll(child, 500, &msg, NULL);
+ ASSERT_EXIT(ret == child_status);
+
+ /*
+ * If we expect the child to get the broadcast
+ * message, then check the received cookie.
+ */
+ if (ret == 0) {
+ ASSERT_EXIT(expected_cookie == msg->cookie);
+ }
+
+ /* Use expected_cookie since 'msg' might be NULL */
+ ret = kdbus_msg_send(child, NULL, expected_cookie + 1,
+ 0, 0, 0, KDBUS_DST_ID_BROADCAST);
+ ASSERT_EXIT(ret == 0);
+
+ kdbus_msg_free(msg);
+ kdbus_conn_free(child);
+ }),
+ ({
+ if (drop_second_user == DO_NOT_DROP) {
+ ASSERT_RETURN(child_2);
+
+ ret = eventfd_read(efd, &event_status);
+ ASSERT_RETURN(ret >= 0 && event_status == 1);
+
+ ret = kdbus_msg_send(child_2, NULL,
+ expected_cookie, 0, 0, 0,
+ KDBUS_DST_ID_BROADCAST);
+ ASSERT_RETURN(ret == 0);
+
+ /* drop own broadcast */
+ ret = kdbus_msg_recv(child_2, &msg, NULL);
+ ASSERT_RETURN(ret == 0);
+ ASSERT_RETURN(msg->src_id == child_2->id);
+ kdbus_msg_free(msg);
+
+ /* Use a little bit high time */
+ ret = kdbus_msg_recv_poll(child_2, 1000,
+ &msg, NULL);
+ ASSERT_RETURN(ret == parent_status);
+
+ /*
+ * Check returned cookie in case we expect
+ * success.
+ */
+ if (ret == 0) {
+ ASSERT_RETURN(msg->cookie ==
+ expected_cookie + 1);
+ }
+
+ kdbus_msg_free(msg);
+ } else {
+ /*
+ * Two unprivileged users will try to
+ * communicate using broadcast.
+ */
+ ret = RUN_UNPRIVILEGED(second_uid, second_gid, ({
+ child_2 = kdbus_hello(bus, 0, NULL, 0);
+ ASSERT_EXIT(child_2);
+
+ ret = kdbus_add_match_empty(child_2);
+ ASSERT_EXIT(ret == 0);
+
+ ret = eventfd_read(efd, &event_status);
+ ASSERT_EXIT(ret >= 0 && event_status == 1);
+
+ ret = kdbus_msg_send(child_2, NULL,
+ expected_cookie, 0, 0, 0,
+ KDBUS_DST_ID_BROADCAST);
+ ASSERT_EXIT(ret == 0);
+
+ /* drop own broadcast */
+ ret = kdbus_msg_recv(child_2, &msg, NULL);
+ ASSERT_RETURN(ret == 0);
+ ASSERT_RETURN(msg->src_id == child_2->id);
+ kdbus_msg_free(msg);
+
+ /* Use a little bit high time */
+ ret = kdbus_msg_recv_poll(child_2, 1000,
+ &msg, NULL);
+ ASSERT_EXIT(ret == parent_status);
+
+ /*
+ * Check returned cookie in case we expect
+ * success.
+ */
+ if (ret == 0) {
+ ASSERT_EXIT(msg->cookie ==
+ expected_cookie + 1);
+ }
+
+ kdbus_msg_free(msg);
+ kdbus_conn_free(child_2);
+ }),
+ ({ 0; }));
+ ASSERT_RETURN(ret == 0);
+ }
+ }));
+ ASSERT_RETURN(ret == 0);
+
+ close(efd);
+
+ return ret;
+}
+
+static void nosig(int sig)
+{
+}
+
+static int test_priv_before_policy_upload(struct kdbus_test_env *env)
+{
+ int ret = 0;
+ struct kdbus_conn *conn;
+
+ conn = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_RETURN(conn);
+
+ /*
+ * Make sure unprivileged bus user cannot acquire names
+ * before registring any policy holder.
+ */
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_name_acquire(unpriv, "com.example.a", NULL);
+ ASSERT_EXIT(ret < 0);
+ }));
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * Make sure unprivileged bus users cannot talk by default
+ * to privileged ones, unless a policy holder that allows
+ * this was uploaded.
+ */
+
+ ret = test_policy_priv_by_id(env->buspath, conn, false,
+ -ETIMEDOUT, -EPERM);
+ ASSERT_RETURN(ret == 0);
+
+ /* Activate matching for a privileged connection */
+ ret = kdbus_add_match_empty(conn);
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * First make sure that BROADCAST with msg flag
+ * KDBUS_MSG_EXPECT_REPLY will fail with -ENOTUNIQ
+ */
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_msg_send(unpriv, NULL, 0xdeadbeef,
+ KDBUS_MSG_EXPECT_REPLY,
+ 5000000000ULL, 0,
+ KDBUS_DST_ID_BROADCAST);
+ ASSERT_EXIT(ret == -ENOTUNIQ);
+ }));
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * Test broadcast with a privileged connection.
+ *
+ * The first unprivileged receiver should not get the
+ * broadcast message sent by the privileged connection,
+ * since there is no a TALK policy that allows the
+ * unprivileged to TALK to the privileged connection. It
+ * will fail with -ETIMEDOUT
+ *
+ * Then second case:
+ * The privileged connection should get the broadcast
+ * message from the unprivileged one. Since the receiver is
+ * a privileged bus user and it has default TALK access to
+ * all connections it will receive those.
+ */
+
+ ret = test_policy_priv_by_broadcast(env->buspath, conn,
+ DO_NOT_DROP,
+ 0, -ETIMEDOUT);
+ ASSERT_RETURN(ret == 0);
+
+
+ /*
+ * Test broadcast with two unprivileged connections running
+ * under the same user.
+ *
+ * Both connections should succeed.
+ */
+
+ ret = test_policy_priv_by_broadcast(env->buspath, NULL,
+ DROP_SAME_UNPRIV, 0, 0);
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * Test broadcast with two unprivileged connections running
+ * under different users.
+ *
+ * Both connections will fail with -ETIMEDOUT.
+ */
+
+ ret = test_policy_priv_by_broadcast(env->buspath, NULL,
+ DROP_OTHER_UNPRIV,
+ -ETIMEDOUT, -ETIMEDOUT);
+ ASSERT_RETURN(ret == 0);
+
+ kdbus_conn_free(conn);
+
+ return ret;
+}
+
+static int test_broadcast_after_policy_upload(struct kdbus_test_env *env)
+{
+ int ret;
+ int efd;
+ eventfd_t event_status = 0;
+ struct kdbus_msg *msg = NULL;
+ struct kdbus_conn *owner_a, *owner_b;
+ struct kdbus_conn *holder_a, *holder_b;
+ struct kdbus_policy_access access = {};
+ uint64_t expected_cookie = time(NULL) ^ 0xdeadbeef;
+
+ owner_a = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_RETURN(owner_a);
+
+ ret = kdbus_name_acquire(owner_a, "com.example.broadcastA", NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ /*
+ * Make sure unprivileged bus users cannot talk by default
+ * to privileged ones, unless a policy holder that allows
+ * this was uploaded.
+ */
+
+ ++expected_cookie;
+ ret = test_policy_priv_by_id(env->buspath, owner_a, false,
+ -ETIMEDOUT, -EPERM);
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * Make sure that privileged won't receive broadcasts unless
+ * it installs a match. It will fail with -ETIMEDOUT
+ *
+ * At same time check that the unprivileged connection will
+ * not receive the broadcast message from the privileged one
+ * since the privileged one owns a name with a restricted
+ * policy TALK (actually the TALK policy is still not
+ * registered so we fail by default), thus the unprivileged
+ * receiver is not able to TALK to that name.
+ */
+
+ /* Activate matching for a privileged connection */
+ ret = kdbus_add_match_empty(owner_a);
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * Redo the previous test. The privileged conn owner_a is
+ * able to TALK to any connection so it will receive the
+ * broadcast message now.
+ */
+
+ ret = test_policy_priv_by_broadcast(env->buspath, owner_a,
+ DO_NOT_DROP,
+ 0, -ETIMEDOUT);
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * Test that broadcast between two unprivileged users running
+ * under the same user still succeed.
+ */
+
+ ret = test_policy_priv_by_broadcast(env->buspath, NULL,
+ DROP_SAME_UNPRIV, 0, 0);
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * Test broadcast with two unprivileged connections running
+ * under different users.
+ *
+ * Both connections will fail with -ETIMEDOUT.
+ */
+
+ ret = test_policy_priv_by_broadcast(env->buspath, NULL,
+ DROP_OTHER_UNPRIV,
+ -ETIMEDOUT, -ETIMEDOUT);
+ ASSERT_RETURN(ret == 0);
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = geteuid(),
+ .access = KDBUS_POLICY_OWN,
+ };
+
+ holder_a = kdbus_hello_registrar(env->buspath,
+ "com.example.broadcastA",
+ &access, 1,
+ KDBUS_HELLO_POLICY_HOLDER);
+ ASSERT_RETURN(holder_a);
+
+ holder_b = kdbus_hello_registrar(env->buspath,
+ "com.example.broadcastB",
+ &access, 1,
+ KDBUS_HELLO_POLICY_HOLDER);
+ ASSERT_RETURN(holder_b);
+
+ /* Free connections and their received messages and restart */
+ kdbus_conn_free(owner_a);
+
+ owner_a = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_RETURN(owner_a);
+
+ /* Activate matching for a privileged connection */
+ ret = kdbus_add_match_empty(owner_a);
+ ASSERT_RETURN(ret == 0);
+
+ ret = kdbus_name_acquire(owner_a, "com.example.broadcastA", NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ owner_b = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_RETURN(owner_b);
+
+ ret = kdbus_name_acquire(owner_b, "com.example.broadcastB", NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ /* Activate matching for a privileged connection */
+ ret = kdbus_add_match_empty(owner_b);
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * Test that even if "com.example.broadcastA" and
+ * "com.example.broadcastB" do have a TALK access by default
+ * they are able to signal each other using broadcast due to
+ * the fact they are privileged connections, they receive
+ * all broadcasts if the match allows it.
+ */
+
+ ++expected_cookie;
+ ret = kdbus_msg_send(owner_a, NULL, expected_cookie, 0,
+ 0, 0, KDBUS_DST_ID_BROADCAST);
+ ASSERT_RETURN(ret == 0);
+
+ ret = kdbus_msg_recv_poll(owner_a, 100, &msg, NULL);
+ ASSERT_RETURN(ret == 0);
+ ASSERT_RETURN(msg->cookie == expected_cookie);
+
+ /* Check src ID */
+ ASSERT_RETURN(msg->src_id == owner_a->id);
+
+ kdbus_msg_free(msg);
+
+ ret = kdbus_msg_recv_poll(owner_b, 100, &msg, NULL);
+ ASSERT_RETURN(ret == 0);
+ ASSERT_RETURN(msg->cookie == expected_cookie);
+
+ /* Check src ID */
+ ASSERT_RETURN(msg->src_id == owner_a->id);
+
+ kdbus_msg_free(msg);
+
+ /* Release name "com.example.broadcastB" */
+
+ ret = kdbus_name_release(owner_b, "com.example.broadcastB");
+ ASSERT_EXIT(ret >= 0);
+
+ /* KDBUS_POLICY_OWN for unprivileged connections */
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_WORLD,
+ .id = geteuid(),
+ .access = KDBUS_POLICY_OWN,
+ };
+
+ /* Update the policy so unprivileged will own the name */
+
+ ret = kdbus_conn_update_policy(holder_b,
+ "com.example.broadcastB",
+ &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * Send broadcasts from an unprivileged connection that
+ * owns a name "com.example.broadcastB".
+ *
+ * We'll have four destinations here:
+ *
+ * 1) destination owner_a: privileged connection that owns
+ * "com.example.broadcastA". It will receive the broadcast
+ * since it is a privileged has default TALK access to all
+ * connections, and it is subscribed to the match.
+ * Will succeed.
+ *
+ * owner_b: privileged connection (running under a different
+ * uid) that do not own names, but with an empty broadcast
+ * match, so it will receive broadcasts since it has default
+ * TALK access to all connection.
+ *
+ * unpriv_a: unpriv connection that do not own any name.
+ * It will receive the broadcast since it is running under
+ * the same user of the one broadcasting and did install
+ * matches. It should get the message.
+ *
+ * unpriv_b: unpriv connection is not interested in broadcast
+ * messages, so it did not install broadcast matches. Should
+ * fail with -ETIMEDOUT
+ */
+
+ ++expected_cookie;
+ efd = eventfd(0, EFD_CLOEXEC);
+ ASSERT_RETURN_VAL(efd >= 0, efd);
+
+ ret = RUN_UNPRIVILEGED(UNPRIV_UID, UNPRIV_UID, ({
+ struct kdbus_conn *unpriv_owner;
+ struct kdbus_conn *unpriv_a, *unpriv_b;
+
+ unpriv_owner = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_EXIT(unpriv_owner);
+
+ unpriv_a = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_EXIT(unpriv_a);
+
+ unpriv_b = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_EXIT(unpriv_b);
+
+ ret = kdbus_name_acquire(unpriv_owner,
+ "com.example.broadcastB",
+ NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ ret = kdbus_add_match_empty(unpriv_a);
+ ASSERT_EXIT(ret == 0);
+
+ /* Signal that we are doing broadcasts */
+ ret = eventfd_write(efd, 1);
+ ASSERT_EXIT(ret == 0);
+
+ /*
+ * Do broadcast from a connection that owns the
+ * names "com.example.broadcastB".
+ */
+ ret = kdbus_msg_send(unpriv_owner, NULL,
+ expected_cookie,
+ 0, 0, 0,
+ KDBUS_DST_ID_BROADCAST);
+ ASSERT_EXIT(ret == 0);
+
+ /*
+ * Unprivileged connection running under the same
+ * user. It should succeed.
+ */
+ ret = kdbus_msg_recv_poll(unpriv_a, 300, &msg, NULL);
+ ASSERT_EXIT(ret == 0 && msg->cookie == expected_cookie);
+
+ /*
+ * Did not install matches, not interested in
+ * broadcasts
+ */
+ ret = kdbus_msg_recv_poll(unpriv_b, 300, NULL, NULL);
+ ASSERT_EXIT(ret == -ETIMEDOUT);
+ }),
+ ({
+ ret = eventfd_read(efd, &event_status);
+ ASSERT_RETURN(ret >= 0 && event_status == 1);
+
+ /*
+ * owner_a must fail with -ETIMEDOUT, since it owns
+ * name "com.example.broadcastA" and its TALK
+ * access is restriced.
+ */
+ ret = kdbus_msg_recv_poll(owner_a, 300, &msg, NULL);
+ ASSERT_RETURN(ret == 0);
+
+ /* confirm the received cookie */
+ ASSERT_RETURN(msg->cookie == expected_cookie);
+
+ kdbus_msg_free(msg);
+
+ /*
+ * owner_b got the broadcast from an unprivileged
+ * connection.
+ */
+ ret = kdbus_msg_recv_poll(owner_b, 300, &msg, NULL);
+ ASSERT_RETURN(ret == 0);
+
+ /* confirm the received cookie */
+ ASSERT_RETURN(msg->cookie == expected_cookie);
+
+ kdbus_msg_free(msg);
+
+ }));
+ ASSERT_RETURN(ret == 0);
+
+ close(efd);
+
+ /*
+ * Test broadcast with two unprivileged connections running
+ * under different users.
+ *
+ * Both connections will fail with -ETIMEDOUT.
+ */
+
+ ret = test_policy_priv_by_broadcast(env->buspath, NULL,
+ DROP_OTHER_UNPRIV,
+ -ETIMEDOUT, -ETIMEDOUT);
+ ASSERT_RETURN(ret == 0);
+
+ /* Drop received broadcasts by privileged */
+ ret = kdbus_msg_recv_poll(owner_a, 100, NULL, NULL);
+ ret = kdbus_msg_recv_poll(owner_a, 100, NULL, NULL);
+ ASSERT_RETURN(ret == 0);
+
+ ret = kdbus_msg_recv(owner_a, NULL, NULL);
+ ASSERT_RETURN(ret == -EAGAIN);
+
+ ret = kdbus_msg_recv_poll(owner_b, 100, NULL, NULL);
+ ret = kdbus_msg_recv_poll(owner_b, 100, NULL, NULL);
+ ASSERT_RETURN(ret == 0);
+
+ ret = kdbus_msg_recv(owner_b, NULL, NULL);
+ ASSERT_RETURN(ret == -EAGAIN);
+
+ /*
+ * Perform last tests, allow others to talk to name
+ * "com.example.broadcastA". So now receiving broadcasts
+ * from it should succeed since the TALK policy allow it.
+ */
+
+ /* KDBUS_POLICY_OWN for unprivileged connections */
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_WORLD,
+ .id = geteuid(),
+ .access = KDBUS_POLICY_TALK,
+ };
+
+ ret = kdbus_conn_update_policy(holder_a,
+ "com.example.broadcastA",
+ &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * Unprivileged is able to TALK to "com.example.broadcastA"
+ * now so it will receive its broadcasts
+ */
+ ret = test_policy_priv_by_broadcast(env->buspath, owner_a,
+ DO_NOT_DROP, 0, 0);
+ ASSERT_RETURN(ret == 0);
+
+ ++expected_cookie;
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_name_acquire(unpriv, "com.example.broadcastB",
+ NULL);
+ ASSERT_EXIT(ret >= 0);
+ ret = kdbus_msg_send(unpriv, NULL, expected_cookie,
+ 0, 0, 0, KDBUS_DST_ID_BROADCAST);
+ ASSERT_EXIT(ret == 0);
+ }));
+ ASSERT_RETURN(ret == 0);
+
+ /* owner_a is privileged it will get the broadcast now. */
+ ret = kdbus_msg_recv_poll(owner_a, 300, &msg, NULL);
+ ASSERT_RETURN(ret == 0);
+
+ /* confirm the received cookie */
+ ASSERT_RETURN(msg->cookie == expected_cookie);
+
+ kdbus_msg_free(msg);
+
+ /*
+ * owner_a released name "com.example.broadcastA". It should
+ * receive broadcasts since it is still privileged and has
+ * the right match.
+ *
+ * Unprivileged connection will own a name and will try to
+ * signal to the privileged connection.
+ */
+
+ ret = kdbus_name_release(owner_a, "com.example.broadcastA");
+ ASSERT_EXIT(ret >= 0);
+
+ ++expected_cookie;
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_name_acquire(unpriv, "com.example.broadcastB",
+ NULL);
+ ASSERT_EXIT(ret >= 0);
+ ret = kdbus_msg_send(unpriv, NULL, expected_cookie,
+ 0, 0, 0, KDBUS_DST_ID_BROADCAST);
+ ASSERT_EXIT(ret == 0);
+ }));
+ ASSERT_RETURN(ret == 0);
+
+ /* owner_a will get the broadcast now. */
+ ret = kdbus_msg_recv_poll(owner_a, 300, &msg, NULL);
+ ASSERT_RETURN(ret == 0);
+
+ /* confirm the received cookie */
+ ASSERT_RETURN(msg->cookie == expected_cookie);
+
+ kdbus_msg_free(msg);
+
+ kdbus_conn_free(owner_a);
+ kdbus_conn_free(owner_b);
+ kdbus_conn_free(holder_a);
+ kdbus_conn_free(holder_b);
+
+ return 0;
+}
+
+static int test_policy_priv(struct kdbus_test_env *env)
+{
+ struct kdbus_conn *conn_a, *conn_b, *conn, *owner;
+ struct kdbus_policy_access access, *acc;
+ sigset_t sset;
+ size_t num;
+ int ret;
+
+ /*
+ * Make sure we have CAP_SETUID/SETGID so we can drop privileges
+ */
+
+ ret = test_is_capable(CAP_SETUID, CAP_SETGID, -1);
+ ASSERT_RETURN(ret >= 0);
+
+ if (!ret)
+ return TEST_SKIP;
+
+ /* make sure that uids and gids are mapped */
+ if (!all_uids_gids_are_mapped())
+ return TEST_SKIP;
+
+ /*
+ * Setup:
+ * conn_a: policy holder for com.example.a
+ * conn_b: name holder of com.example.b
+ */
+
+ signal(SIGUSR1, nosig);
+ sigemptyset(&sset);
+ sigaddset(&sset, SIGUSR1);
+ sigprocmask(SIG_BLOCK, &sset, NULL);
+
+ conn = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_RETURN(conn);
+
+ /*
+ * Before registering any policy holder, make sure that the
+ * bus is secure by default. This test is necessary, it catches
+ * several cases where old D-Bus was vulnerable.
+ */
+
+ ret = test_priv_before_policy_upload(env);
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * Make sure unprivileged are not able to register policy
+ * holders
+ */
+
+ ret = RUN_UNPRIVILEGED(UNPRIV_UID, UNPRIV_GID, ({
+ struct kdbus_conn *holder;
+
+ holder = kdbus_hello_registrar(env->buspath,
+ "com.example.a", NULL, 0,
+ KDBUS_HELLO_POLICY_HOLDER);
+ ASSERT_EXIT(holder == NULL && errno == EPERM);
+ }),
+ ({ 0; }));
+ ASSERT_RETURN(ret == 0);
+
+
+ /* Register policy holder */
+
+ conn_a = kdbus_hello_registrar(env->buspath, "com.example.a",
+ NULL, 0, KDBUS_HELLO_POLICY_HOLDER);
+ ASSERT_RETURN(conn_a);
+
+ conn_b = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_RETURN(conn_b);
+
+ ret = kdbus_name_acquire(conn_b, "com.example.b", NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ /*
+ * Make sure bus-owners can always acquire names.
+ */
+ ret = kdbus_name_acquire(conn, "com.example.a", NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ kdbus_conn_free(conn);
+
+ /*
+ * Make sure unprivileged users cannot acquire names with default
+ * policy assigned.
+ */
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_name_acquire(unpriv, "com.example.a", NULL);
+ ASSERT_EXIT(ret < 0);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ /*
+ * Make sure unprivileged users can acquire names if we make them
+ * world-accessible.
+ */
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_WORLD,
+ .id = 0,
+ .access = KDBUS_POLICY_OWN,
+ };
+
+ /*
+ * Make sure unprivileged/normal connections are not able
+ * to update policies
+ */
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_conn_update_policy(unpriv, "com.example.a",
+ &access, 1);
+ ASSERT_EXIT(ret == -EOPNOTSUPP);
+ }));
+ ASSERT_RETURN(ret == 0);
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.a", &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_name_acquire(unpriv, "com.example.a", NULL);
+ ASSERT_EXIT(ret >= 0);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ /*
+ * Make sure unprivileged users can acquire names if we make them
+ * gid-accessible. But only if the gid matches.
+ */
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_GROUP,
+ .id = UNPRIV_GID,
+ .access = KDBUS_POLICY_OWN,
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.a", &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_name_acquire(unpriv, "com.example.a", NULL);
+ ASSERT_EXIT(ret >= 0);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_GROUP,
+ .id = 1,
+ .access = KDBUS_POLICY_OWN,
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.a", &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_name_acquire(unpriv, "com.example.a", NULL);
+ ASSERT_EXIT(ret < 0);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ /*
+ * Make sure unprivileged users can acquire names if we make them
+ * uid-accessible. But only if the uid matches.
+ */
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = UNPRIV_UID,
+ .access = KDBUS_POLICY_OWN,
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.a", &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_name_acquire(unpriv, "com.example.a", NULL);
+ ASSERT_EXIT(ret >= 0);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = 1,
+ .access = KDBUS_POLICY_OWN,
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.a", &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_name_acquire(unpriv, "com.example.a", NULL);
+ ASSERT_EXIT(ret < 0);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ /*
+ * Make sure unprivileged users cannot acquire names if no owner-policy
+ * matches, even if SEE/TALK policies match.
+ */
+
+ num = 4;
+ acc = (struct kdbus_policy_access[]){
+ {
+ .type = KDBUS_POLICY_ACCESS_GROUP,
+ .id = UNPRIV_GID,
+ .access = KDBUS_POLICY_SEE,
+ },
+ {
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = UNPRIV_UID,
+ .access = KDBUS_POLICY_TALK,
+ },
+ {
+ .type = KDBUS_POLICY_ACCESS_WORLD,
+ .id = 0,
+ .access = KDBUS_POLICY_TALK,
+ },
+ {
+ .type = KDBUS_POLICY_ACCESS_WORLD,
+ .id = 0,
+ .access = KDBUS_POLICY_SEE,
+ },
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.a", acc, num);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_name_acquire(unpriv, "com.example.a", NULL);
+ ASSERT_EXIT(ret < 0);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ /*
+ * Make sure unprivileged users can acquire names if the only matching
+ * policy is somewhere in the middle.
+ */
+
+ num = 5;
+ acc = (struct kdbus_policy_access[]){
+ {
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = 1,
+ .access = KDBUS_POLICY_OWN,
+ },
+ {
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = 2,
+ .access = KDBUS_POLICY_OWN,
+ },
+ {
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = UNPRIV_UID,
+ .access = KDBUS_POLICY_OWN,
+ },
+ {
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = 3,
+ .access = KDBUS_POLICY_OWN,
+ },
+ {
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = 4,
+ .access = KDBUS_POLICY_OWN,
+ },
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.a", acc, num);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_name_acquire(unpriv, "com.example.a", NULL);
+ ASSERT_EXIT(ret >= 0);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ /*
+ * Clear policies
+ */
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.a", NULL, 0);
+ ASSERT_RETURN(ret == 0);
+
+ /*
+ * Make sure privileged bus users can _always_ talk to others.
+ */
+
+ conn = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_RETURN(conn);
+
+ ret = kdbus_msg_send(conn, "com.example.b", 0xdeadbeef, 0, 0, 0, 0);
+ ASSERT_EXIT(ret >= 0);
+
+ ret = kdbus_msg_recv_poll(conn_b, 300, NULL, NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ kdbus_conn_free(conn);
+
+ /*
+ * Make sure unprivileged bus users cannot talk by default.
+ */
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_msg_send(unpriv, "com.example.b", 0xdeadbeef, 0, 0,
+ 0, 0);
+ ASSERT_EXIT(ret == -EPERM);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ /*
+ * Make sure unprivileged bus users can talk to equals, even without
+ * policy.
+ */
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = UNPRIV_UID,
+ .access = KDBUS_POLICY_OWN,
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.c", &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ struct kdbus_conn *owner;
+
+ owner = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_RETURN(owner);
+
+ ret = kdbus_name_acquire(owner, "com.example.c", NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ ret = kdbus_msg_send(unpriv, "com.example.c", 0xdeadbeef, 0, 0,
+ 0, 0);
+ ASSERT_EXIT(ret >= 0);
+ ret = kdbus_msg_recv_poll(owner, 100, NULL, NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ kdbus_conn_free(owner);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ /*
+ * Make sure unprivileged bus users can talk to privileged users if a
+ * suitable UID policy is set.
+ */
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = UNPRIV_UID,
+ .access = KDBUS_POLICY_TALK,
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.b", &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_msg_send(unpriv, "com.example.b", 0xdeadbeef, 0, 0,
+ 0, 0);
+ ASSERT_EXIT(ret >= 0);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ ret = kdbus_msg_recv_poll(conn_b, 100, NULL, NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ /*
+ * Make sure unprivileged bus users can talk to privileged users if a
+ * suitable GID policy is set.
+ */
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_GROUP,
+ .id = UNPRIV_GID,
+ .access = KDBUS_POLICY_TALK,
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.b", &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_msg_send(unpriv, "com.example.b", 0xdeadbeef, 0, 0,
+ 0, 0);
+ ASSERT_EXIT(ret >= 0);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ ret = kdbus_msg_recv_poll(conn_b, 100, NULL, NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ /*
+ * Make sure unprivileged bus users can talk to privileged users if a
+ * suitable WORLD policy is set.
+ */
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_WORLD,
+ .id = 0,
+ .access = KDBUS_POLICY_TALK,
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.b", &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_msg_send(unpriv, "com.example.b", 0xdeadbeef, 0, 0,
+ 0, 0);
+ ASSERT_EXIT(ret >= 0);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ ret = kdbus_msg_recv_poll(conn_b, 100, NULL, NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ /*
+ * Make sure unprivileged bus users cannot talk to privileged users if
+ * no suitable policy is set.
+ */
+
+ num = 5;
+ acc = (struct kdbus_policy_access[]){
+ {
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = 0,
+ .access = KDBUS_POLICY_OWN,
+ },
+ {
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = 1,
+ .access = KDBUS_POLICY_TALK,
+ },
+ {
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = UNPRIV_UID,
+ .access = KDBUS_POLICY_SEE,
+ },
+ {
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = 3,
+ .access = KDBUS_POLICY_TALK,
+ },
+ {
+ .type = KDBUS_POLICY_ACCESS_USER,
+ .id = 4,
+ .access = KDBUS_POLICY_TALK,
+ },
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.b", acc, num);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_msg_send(unpriv, "com.example.b", 0xdeadbeef, 0, 0,
+ 0, 0);
+ ASSERT_EXIT(ret == -EPERM);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ /*
+ * Make sure unprivileged bus users can talk to privileged users if a
+ * suitable OWN privilege overwrites TALK.
+ */
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_WORLD,
+ .id = 0,
+ .access = KDBUS_POLICY_OWN,
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.b", &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_msg_send(unpriv, "com.example.b", 0xdeadbeef, 0, 0,
+ 0, 0);
+ ASSERT_EXIT(ret >= 0);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ ret = kdbus_msg_recv_poll(conn_b, 100, NULL, NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ /*
+ * Make sure the TALK cache is reset correctly when policies are
+ * updated.
+ */
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_WORLD,
+ .id = 0,
+ .access = KDBUS_POLICY_TALK,
+ };
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.b", &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ ret = RUN_UNPRIVILEGED_CONN(unpriv, env->buspath, ({
+ ret = kdbus_msg_send(unpriv, "com.example.b", 0xdeadbeef, 0, 0,
+ 0, 0);
+ ASSERT_EXIT(ret >= 0);
+
+ ret = kdbus_msg_recv_poll(conn_b, 100, NULL, NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ ret = kdbus_conn_update_policy(conn_a, "com.example.b",
+ NULL, 0);
+ ASSERT_RETURN(ret == 0);
+
+ ret = kdbus_msg_send(unpriv, "com.example.b", 0xdeadbeef, 0, 0,
+ 0, 0);
+ ASSERT_EXIT(ret == -EPERM);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+ /*
+ * Make sure the TALK cache is reset correctly when policy holders
+ * disconnect.
+ */
+
+ access = (struct kdbus_policy_access){
+ .type = KDBUS_POLICY_ACCESS_WORLD,
+ .id = 0,
+ .access = KDBUS_POLICY_OWN,
+ };
+
+ conn = kdbus_hello_registrar(env->buspath, "com.example.c",
+ NULL, 0, KDBUS_HELLO_POLICY_HOLDER);
+ ASSERT_RETURN(conn);
+
+ ret = kdbus_conn_update_policy(conn, "com.example.c", &access, 1);
+ ASSERT_RETURN(ret == 0);
+
+ owner = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_RETURN(owner);
+
+ ret = kdbus_name_acquire(owner, "com.example.c", NULL);
+ ASSERT_RETURN(ret >= 0);
+
+ ret = RUN_UNPRIVILEGED(UNPRIV_UID, UNPRIV_GID, ({
+ struct kdbus_conn *unpriv;
+
+ /* wait for parent to be finished */
+ sigemptyset(&sset);
+ ret = sigsuspend(&sset);
+ ASSERT_RETURN(ret == -1 && errno == EINTR);
+
+ unpriv = kdbus_hello(env->buspath, 0, NULL, 0);
+ ASSERT_RETURN(unpriv);
+
+ ret = kdbus_msg_send(unpriv, "com.example.c", 0xdeadbeef, 0, 0,
+ 0, 0);
+ ASSERT_EXIT(ret >= 0);
+
+ ret = kdbus_msg_recv_poll(owner, 100, NULL, NULL);
+ ASSERT_EXIT(ret >= 0);
+
+ /* free policy holder */
+ kdbus_conn_free(conn);
+
+ ret = kdbus_msg_send(unpriv, "com.example.c", 0xdeadbeef, 0, 0,
+ 0, 0);
+ ASSERT_EXIT(ret == -EPERM);
+
+ kdbus_conn_free(unpriv);
+ }), ({
+ /* make sure policy holder is only valid in child */
+ kdbus_conn_free(conn);
+ kill(pid, SIGUSR1);
+ }));
+ ASSERT_RETURN(ret >= 0);
+
+
+ /*
+ * The following tests are necessary.
+ */
+
+ ret = test_broadcast_after_policy_upload(env);
+ ASSERT_RETURN(ret == 0);
+
+ kdbus_conn_free(owner);
+
+ /*
+ * cleanup resources
+ */
+
+ kdbus_conn_free(conn_b);
+ kdbus_conn_free(conn_a);
+
+ return TEST_OK;
+}
+
+int kdbus_test_policy_priv(struct kdbus_test_env *env)
+{
+ pid_t pid;
+ int ret;
+
+ /* make sure to exit() if a child returns from fork() */
+ pid = getpid();
+ ret = test_policy_priv(env);
+ if (pid != getpid())
+ exit(1);
+
+ return ret;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-25 20:38:54 +0000