From cef40299a93233f043f5b0821a9ad2c69dd612f7 Mon Sep 17 00:00:00 2001 From: Alvar Date: Fri, 6 Feb 2026 11:58:38 +0000 Subject: OpenBSD: pledge(2) some network-facing checks (#2225) OpenBSD's pledge(2) system call allows the current process to self-restrict itself, being reduced to promised pledges. For example, unless a process says it wants to write to files, it is not allowed to do so any longer. This change starts by calling pledge(2) in some network-facing checks, removing the more dangerous privileges, such as executing other files. My initial motivation came from check_icmp, being installed as a setuid binary and (temporarily) running with root privileges. There, the pledge(2) calls result in check_icmp to only being allowed to interact with the network and to setuid(2) to the calling user later on. Afterwards, I went through my most commonly used monitoring plugins directly interacting with the network. Thus, I continued with pledge(2)-ing check_curl - having a huge codebase and all -, check_ntp_time, check_smtp, check_ssh, and check_tcp. For most of those, the changes were quite similar: start with network-friendly promises, parse the configuration, give up file access, and proceed with the actual check. --- plugins/check_curl.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'plugins/check_curl.c') diff --git a/plugins/check_curl.c b/plugins/check_curl.c index 1dec8a2a..19d36237 100644 --- a/plugins/check_curl.c +++ b/plugins/check_curl.c @@ -120,6 +120,14 @@ mp_state_enum np_net_ssl_check_certificate(X509 *certificate, int days_till_exp_ #endif /* defined(HAVE_SSL) && defined(USE_OPENSSL) */ int main(int argc, char **argv) { +#ifdef __OpenBSD__ + /* - rpath is required to read --extra-opts, CA and/or client certs + * - wpath is required to write --cookie-jar (possibly given up later) + * - inet is required for sockets + * - dns is required for name lookups */ + pledge("stdio rpath wpath inet dns", NULL); +#endif // __OpenBSD__ + setlocale(LC_ALL, ""); bindtextdomain(PACKAGE, LOCALEDIR); textdomain(PACKAGE); @@ -135,6 +143,15 @@ int main(int argc, char **argv) { const check_curl_config config = tmp_config.config; +#ifdef __OpenBSD__ + if (!config.curl_config.cookie_jar_file) { + if (verbose >= 2) { + printf(_("* No \"--cookie-jar\" is used, giving up \"wpath\" pledge(2)\n")); + } + pledge("stdio rpath inet dns", NULL); + } +#endif // __OpenBSD__ + if (config.output_format_is_set) { mp_set_format(config.output_format); } -- cgit v1.2.3-74-g34f1