From: Michal Nowak <mnowak@isc.org>
Date: Mon, 29 Jun 2026 11:40:50 +0000 (+0000)
Subject: Assert fd validity in start_udp_child()
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=992674e3509112107fd6aa2a14ca0daa5313dd35;p=thirdparty%2Fbind9.git

Assert fd validity in start_udp_child()

load_balance_sockets is fixed at netmgr init, so dup(fd) runs only when
the caller supplied a valid descriptor.  Assert it to silence a
scan-build false positive:

    lib/isc/netmgr/udp.c:194:15: warning: The 1st argument to 'dup' is -1 but should be >= 0 [unix.StdCLibraryFunctions]

Assisted-by: Claude:claude-opus-4-8
---

diff --git a/lib/isc/netmgr/udp.c b/lib/isc/netmgr/udp.c
index 7922683bdc9..fa79717fb77 100644
--- a/lib/isc/netmgr/udp.c
+++ b/lib/isc/netmgr/udp.c
@@ -191,6 +191,7 @@ start_udp_child(isc_sockaddr_t *iface, isc_nmsocket_t *sock, uv_os_sock_t fd,
 	if (isc__netmgr->load_balance_sockets) {
 		csock->fd = isc__nm_udp_lb_socket(iface->type.sa.sa_family);
 	} else {
+		INSIST(fd >= 0);
 		csock->fd = dup(fd);
 	}
 	INSIST(csock->fd >= 0);