Index: sys/netinet/tcp_hostcache.c
===================================================================
--- sys/netinet/tcp_hostcache.c
+++ sys/netinet/tcp_hostcache.c
@@ -69,10 +69,12 @@
 
 #include <sys/param.h>
 #include <sys/systm.h>
+#include <sys/jail.h>
 #include <sys/kernel.h>
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/malloc.h>
+#include <sys/proc.h>
 #include <sys/sbuf.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
@@ -625,6 +627,9 @@
 	char ip6buf[INET6_ADDRSTRLEN];
 #endif
 
+	if (jailed_without_vnet(curthread->td_ucred) != 0)
+		return (EPERM);
+
 	sbuf_new(&sb, NULL, linesize * (V_tcp_hostcache.cache_count + 1),
 		SBUF_INCLUDENUL);