Index: sys/kern/uipc_sockbuf.c
===================================================================
--- sys/kern/uipc_sockbuf.c
+++ sys/kern/uipc_sockbuf.c
@@ -693,7 +693,8 @@
 			if (*lowat > *hiwat)
 				*lowat = *hiwat;
 		} else {
-			if (!sbreserve_locked(sb, cc, so, curthread))
+                        u_long limit = sogetmaxbuf(so);
+			if (!sbreserve_locked_limit(sb, cc, so, limit, curthread))
 				error = ENOBUFS;
 		}
 		if (error == 0)
Index: sys/kern/uipc_socket.c
===================================================================
--- sys/kern/uipc_socket.c
+++ sys/kern/uipc_socket.c
@@ -128,6 +128,7 @@
 #include <sys/event.h>
 #include <sys/eventhandler.h>
 #include <sys/poll.h>
+#include <sys/priv.h>
 #include <sys/proc.h>
 #include <sys/protosw.h>
 #include <sys/sbuf.h>
@@ -2975,6 +2976,15 @@
 	return (0);
 }
 
+u_long
+sogetmaxbuf(struct socket *so)
+{
+	if (so->so_proto->pr_domain->dom_family != PF_NETLINK)
+		return (sb_max);
+	u_long nl_maxsockbuf = 512 * 1024 * 1024; /* 512M, XXX: init based on physmem */
+	return ((priv_check(curthread, PRIV_NET_ROUTE) == 0) ? nl_maxsockbuf : sb_max);
+}
+
 /*
  * Kernel version of setsockopt(2).
  *
Index: sys/sys/sockopt.h
===================================================================
--- sys/sys/sockopt.h
+++ sys/sys/sockopt.h
@@ -68,5 +68,6 @@
 int	accept_filt_setopt(struct socket *, struct sockopt *);
 int	so_setsockopt(struct socket *so, int level, int optname,
 	    void *optval, size_t optlen);
+u_long	sogetmaxbuf(struct socket *so);
 
 #endif /* _SYS_SOCKOPT_H_ */