From: Aram Sargsyan <aram@isc.org>
Date: Wed, 22 Jul 2026 15:48:42 +0000 (+0000)
Subject: Initialize struct sockaddr_nl sa
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=be1119a162b973a502df73cb1751108234502d34;p=thirdparty%2Fbind9.git

Initialize struct sockaddr_nl sa

The structure is initialized, which can cause problems e.g. with
its nl_pid member.

To quote from an LLM report in GL#6257:

> A non-zero nl_pid is an explicit netlink port-ID request, so the
> kernel either binds the socket to an arbitrary port ID (functionally
> tolerable for a multicast-only listener, but it can squat another
> process's natural port ID) or fails with EADDRINUSE when the garbage
> value collides with an existing NETLINK_ROUTE socket in the same
> namespace.

Zero initialize the structure.
---

diff --git a/lib/isc/netmgr/udp.c b/lib/isc/netmgr/udp.c
index 6f544e0d7d1..02402e640c1 100644
--- a/lib/isc/netmgr/udp.c
+++ b/lib/isc/netmgr/udp.c
@@ -372,7 +372,7 @@ static isc_result_t
 route_socket(uv_os_sock_t *fdp) {
 	uv_os_sock_t fd = -1;
 #ifdef USE_NETLINK
-	struct sockaddr_nl sa;
+	struct sockaddr_nl sa = { 0 };
 	int r;
 #endif