selftests/landlock: Fix socket file descriptor leaks in audit helpers

audit_init() opens a netlink socket and configures it, but leaks the
file descriptor if audit_set_status() or setsockopt() fails.  Fix this
by jumping to an error path that closes the socket before returning.

Apply the same fix to audit_init_with_exe_filter(), which leaks the file
descriptor from audit_init() if audit_init_filter_exe() or
audit_filter_exe() fails, and to audit_cleanup(), which leaks it if
audit_init_filter_exe() fails in FIXTURE_TEARDOWN_PARENT().

Cc: Günther Noack <gnoack@google.com>
Cc: stable@vger.kernel.org
Fixes: 6a500b22971c ("selftests/landlock: Add tests for audit flags and domain IDs")
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20260402192608.1458252-3-mic@digikod.net
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 1049a0582af5d4a606946b04bfc102a46fe8cc30..6422943fc69e1918d68f141eefc781b095360559 100644 (file)
--- a/tools/testing/selftests/landlock/audit.h
+++ b/tools/testing/selftests/landlock/audit.h
@@ -379,19 +379,25 @@ static int audit_init(void)
 
        err = audit_set_status(fd, AUDIT_STATUS_ENABLED, 1);
        if (err)
-               return err;
+               goto err_close;
 
        err = audit_set_status(fd, AUDIT_STATUS_PID, getpid());
        if (err)
-               return err;
+               goto err_close;
 
        /* Sets a timeout for negative tests. */
        err = setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &audit_tv_default,
                         sizeof(audit_tv_default));
-       if (err)
-               return -errno;
+       if (err) {
+               err = -errno;
+               goto err_close;
+       }
 
        return fd;
+
+err_close:
+       close(fd);
+       return err;
 }
 
 static int audit_init_filter_exe(struct audit_filter *filter, const char *path)
@@ -441,8 +447,10 @@ static int audit_cleanup(int audit_fd, struct audit_filter *filter)
 
                filter = &new_filter;
                err = audit_init_filter_exe(filter, NULL);
-               if (err)
+               if (err) {
+                       close(audit_fd);
                        return err;
+               }
        }
 
        /* Filters might not be in place. */
@@ -468,11 +476,15 @@ static int audit_init_with_exe_filter(struct audit_filter *filter)
 
        err = audit_init_filter_exe(filter, NULL);
        if (err)
-               return err;
+               goto err_close;
 
        err = audit_filter_exe(fd, filter, AUDIT_ADD_RULE);
        if (err)
-               return err;
+               goto err_close;
 
        return fd;
+
+err_close:
+       close(fd);
+       return err;
 }