From d5e7d9425f4ca7758f7fb4cc1788816ff606e245 Mon Sep 17 00:00:00 2001
From: tuexen <tuexen@FreeBSD.org>
Date: Mon, 17 Feb 2020 14:54:21 +0000
Subject: [PATCH] Don't use uninitialised stack memory if the sysctl variable
 net.inet.tcp.hostcache.enable is set to 0. The bug resulted in using possibly
 a too small MSS value or wrong initial retransmission timer settings.
 Possibly the value used for ssthresh was also wrong.

Submitted by:		Richard Scheffenegger
Reviewed by:		Cheng Cui, rgrimes@, tuexen@
MFC after:		1 week
Differential Revision:	https://reviews.freebsd.org/D23687
---
 sys/netinet/tcp_hostcache.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sys/netinet/tcp_hostcache.c b/sys/netinet/tcp_hostcache.c
index 1b4dc0d24655..2753d511c9d5 100644
--- a/sys/netinet/tcp_hostcache.c
+++ b/sys/netinet/tcp_hostcache.c
@@ -437,8 +437,10 @@ tcp_hc_get(struct in_conninfo *inc, struct hc_metrics_lite *hc_metrics_lite)
 {
 	struct hc_metrics *hc_entry;
 
-	if (!V_tcp_use_hostcache)
+	if (!V_tcp_use_hostcache) {
+		bzero(hc_metrics_lite, sizeof(*hc_metrics_lite));
 		return;
+	}
 
 	/*
 	 * Find the right bucket.