Don't let dbus-daemon and its subprocesses inherit unnecessary fds

This should avoid test failures under CMake in which the
dbus-daemon inherits an unwanted fd from CMake's test framework, causing
the close-on-exec check before executing activated services to fail.

The dbus-daemon now marks all fds that it inherits, except for its
stdin, stdout and stderr, to be closed on exec. For completeness, the
dbus-daemons run by dbus-run-session and dbus-launch also now inherit
stdin, stdout, stderr and the pipes used to communicate with their
callers, but nothing else.

Signed-off-by: Simon McVittie <smcv@collabora.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/bus/main.c b/bus/main.c
index 6e8859aa..84f601b3 100644
--- a/bus/main.c
+++ b/bus/main.c
@@ -423,6 +423,10 @@ main (int argc, char **argv)
                error_str, _dbus_strerror (errno));
       return 1;
     }
+
+  /* Set all fds >= 3 close-on-execute. We don't want activated services
+   * to inherit fds we might have inherited from our caller. */
+  _dbus_fd_set_all_close_on_exec ();
 #endif
 
   if (!_dbus_string_init (&config_file))