selftests/landlock: Explicitly disable audit in teardowns

I'm seeing sporadic selftest failures, such as

  #  RUN           scoped_audit.connect_to_child ...
  # scoped_abstract_unix_test.c:314:connect_to_child:Expected 0 (0) == records.access (8)
  # connect_to_child: Test failed
  #          FAIL  scoped_audit.connect_to_child
  not ok 19 scoped_audit.connect_to_child

This seems similar to what commit 3647a4977fb73d ("selftests/landlock:
Drain stale audit records on init") tried to fix. However, the added
drain loop is not effective. When setting the AUDIT_STATUS_PID, the
kauditd_thread is woken up starting to send messages from the hold queue
to the netlink. Depending on scheduling of this kthread not all messages
might be send via the netlink in the 1 us interval.

Therefore, instead of trying to drain the queue, let's just disable
audit when running non-audit tests or more precisely disable it after
audit-tests. This way we won't generate any new audit message that could
interfere with the other tests.

The comment saying that on process exit audit will be disabled is wrong.
The closed file descriptor just causes an auditd_reset(), not a
disablement. So future messages will be queued in the hold queue.

Cc: stable@vger.kernel.org
Fixes: 6a500b22971c ("selftests/landlock: Add tests for audit flags and domain IDs")
Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
Link: https://patch.msgid.link/20260529-welsh-nagoya-b4d9ca60@mheyne-amazon
[mic: Fix FD leak, update subject, call audit_cleanup() in audit_exec teardown]
Signed-off-by: Mickaël Salaün <mic@digikod.net>

diff --git a/tools/testing/selftests/landlock/audit.h b/tools/testing/selftests/landlock/audit.h
index 936fe20f020e68612a1b39f4cbaf82c4b2fb4c76..f45fdef35681a75a78048b9a81ffba0fead06649 100644 (file)
--- a/tools/testing/selftests/landlock/audit.h
+++ b/tools/testing/selftests/landlock/audit.h
@@ -553,10 +553,9 @@ static int audit_init_filter_exe(struct audit_filter *filter, const char *path)
 static int audit_cleanup(int audit_fd, struct audit_filter *filter)
 {
        struct audit_filter new_filter;
+       int err = 0;
 
        if (audit_fd < 0 || !filter) {
-               int err;
-
                /*
                 * Simulates audit_init_with_exe_filter() when called from
                 * FIXTURE_TEARDOWN_PARENT().
@@ -567,23 +566,19 @@ static int audit_cleanup(int audit_fd, struct audit_filter *filter)
 
                filter = &new_filter;
                err = audit_init_filter_exe(filter, NULL);
-               if (err) {
-                       close(audit_fd);
-                       return err;
-               }
+               if (err)
+                       goto err_close;
        }
 
        /* Filters might not be in place. */
        audit_filter_exe(audit_fd, filter, AUDIT_DEL_RULE);
        audit_filter_drop(audit_fd, AUDIT_DEL_RULE);
 
-       /*
-        * Because audit_cleanup() might not be called by the test auditd
-        * process, it might not be possible to explicitly set it.  Anyway,
-        * AUDIT_STATUS_ENABLED will implicitly be set to 0 when the auditd
-        * process will exit.
-        */
-       return close(audit_fd);
+       err = audit_set_status(audit_fd, AUDIT_STATUS_ENABLED, 0);
+
+err_close:
+       close(audit_fd);
+       return err;
 }
 
 static int audit_init_with_exe_filter(struct audit_filter *filter)

diff --git a/tools/testing/selftests/landlock/audit_test.c b/tools/testing/selftests/landlock/audit_test.c
index 758cf2368281c5d5a9ec80805c226e7f15756ed6..bd9f207b36e40dce543d38e4fc1de7e5c14b0a27 100644 (file)
--- a/tools/testing/selftests/landlock/audit_test.c
+++ b/tools/testing/selftests/landlock/audit_test.c
@@ -850,10 +850,8 @@ FIXTURE_SETUP(audit_exec)
 FIXTURE_TEARDOWN(audit_exec)
 {
        set_cap(_metadata, CAP_AUDIT_CONTROL);
-       EXPECT_EQ(0, audit_filter_exe(self->audit_fd, &self->audit_filter,
-                                     AUDIT_DEL_RULE));
+       EXPECT_EQ(0, audit_cleanup(self->audit_fd, &self->audit_filter));
        clear_cap(_metadata, CAP_AUDIT_CONTROL);
-       EXPECT_EQ(0, close(self->audit_fd));
 }
 
 TEST_F(audit_exec, signal_and_open)