From 6857a112296dee96966212a88bf671bd76467d95 Mon Sep 17 00:00:00 2001
From: Phil Sutter <psutter@redhat.com>
Date: Mon, 24 Feb 2020 16:14:16 +0100
Subject: [PATCH] xtables-monitor: Fix segfault when tracing

This is a minimal fix extracted from upstream commit d0446ab11182f
("xtables: Review nft_init()") which was deemed too untrusive for late
inclusion into RHEL8.2.

(cherry picked from commit e6445667fd0f141ca301aeabeee312545dbf014a)
Signed-off-by: Phil Sutter <psutter@redhat.com>
---
 iptables/xtables-monitor.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/iptables/xtables-monitor.c b/iptables/xtables-monitor.c
index a5245d1422af9..737c35f2ac60c 100644
--- a/iptables/xtables-monitor.c
+++ b/iptables/xtables-monitor.c
@@ -595,7 +595,9 @@ int xtables_monitor_main(int argc, char *argv[])
 	struct mnl_socket *nl;
 	char buf[MNL_SOCKET_BUFFER_SIZE];
 	uint32_t nfgroup = 0;
-	struct nft_handle h = {};
+	struct nft_handle h = {
+		.family = AF_INET,
+	};
 	struct cb_arg cb_arg = {
 		.h = &h,
 	};
@@ -622,6 +624,9 @@ int xtables_monitor_main(int argc, char *argv[])
 			strerror(errno));
 		exit(EXIT_FAILURE);
 	}
+	h.ops = nft_family_ops_lookup(h.family);
+	if (!h.ops)
+		xtables_error(PARAMETER_PROBLEM, "Unknown family");
 
 	opterr = 0;
 	while ((c = getopt_long(argc, argv, "ceht46V", options, NULL)) != -1) {
-- 
2.25.1