RIP6, CAN, SCTP and SCTP6 lack a length check in their _send() functi…

…ons.

Fix RIP6 and CAN, add a big XXX in the SCTP ones.

Found by KASAN, triggered by SyzKaller.

Reported-by: syzbot+0b9692ae0f49f93b7dc7@syzkaller.appspotmail.com

sys/netcan/can_pcb.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: can_pcb.c,v 1.6 2017/06/09 08:21:41 bouyer Exp $	*/
+/*	$NetBSD: can_pcb.c,v 1.7 2019/02/25 06:49:44 maxv Exp $	*/
 
 /*-
  * Copyright (c) 2003, 2017 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: can_pcb.c,v 1.6 2017/06/09 08:21:41 bouyer Exp $");
+__KERNEL_RCSID(0, "$NetBSD: can_pcb.c,v 1.7 2019/02/25 06:49:44 maxv Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -124,6 +124,8 @@ can_pcbbind(void *v, struct sockaddr_can *scan, struct lwp *l)
 
 	if (scan->can_family != AF_CAN)
 		return (EAFNOSUPPORT);
+	if (scan->can_len != sizeof(*scan))
+		return EINVAL;
 	mutex_enter(&canp->canp_mtx);
 	if (scan->can_ifindex != 0) {
 		canp->canp_ifp = if_byindex(scan->can_ifindex);
@@ -157,6 +159,8 @@ can_pcbconnect(void *v, struct sockaddr_can *scan)
 
 	if (scan->can_family != AF_CAN)
 		return (EAFNOSUPPORT);
+	if (scan->can_len != sizeof(*scan))
+		return EINVAL;
 #if 0
 	mutex_enter(&canp->canp_mtx);
 	memcpy(&canp->canp_dst, scan, sizeof(struct sockaddr_can));

sys/netinet/sctp_usrreq.c

@@ -1,5 +1,5 @@
 /*	$KAME: sctp_usrreq.c,v 1.50 2005/06/16 20:45:29 jinmei Exp $	*/
-/*	$NetBSD: sctp_usrreq.c,v 1.17 2019/02/24 07:20:33 maxv Exp $	*/
+/*	$NetBSD: sctp_usrreq.c,v 1.18 2019/02/25 06:49:44 maxv Exp $	*/
 
 /*
  * Copyright (c) 2001, 2002, 2003, 2004 Cisco Systems, Inc.
@@ -33,7 +33,7 @@
  * SUCH DAMAGE.
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sctp_usrreq.c,v 1.17 2019/02/24 07:20:33 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sctp_usrreq.c,v 1.18 2019/02/25 06:49:44 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -638,6 +638,11 @@ sctp_send(struct socket *so, struct mbuf *m, struct sockaddr *addr,
 		return EINVAL;
 	}
 #endif /* INET6 */
+
+	/*
+	 * XXX XXX XXX Check addr->sa_len?
+	 */
+
  connected_type:
 	/* now what about control */
 	if (control) {

sys/netinet6/raw_ip6.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: raw_ip6.c,v 1.174 2019/02/24 07:20:33 maxv Exp $	*/
+/*	$NetBSD: raw_ip6.c,v 1.175 2019/02/25 06:49:44 maxv Exp $	*/
 /*	$KAME: raw_ip6.c,v 1.82 2001/07/23 18:57:56 jinmei Exp $	*/
 
 /*
@@ -62,7 +62,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: raw_ip6.c,v 1.174 2019/02/24 07:20:33 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: raw_ip6.c,v 1.175 2019/02/25 06:49:44 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ipsec.h"
@@ -891,6 +891,10 @@ rip6_send(struct socket *so, struct mbuf *m, struct sockaddr *nam,
 			error = EAFNOSUPPORT;
 			goto release;
 		}
+		if (dst->sin6_len != sizeof(*dst)) {
+			error = EINVAL;
+			goto release;
+		}
 	}
 	error = rip6_output(m, so, dst, control);
 	m = NULL;

sys/netinet6/sctp6_usrreq.c

@@ -1,5 +1,5 @@
 /* $KAME: sctp6_usrreq.c,v 1.38 2005/08/24 08:08:56 suz Exp $ */
-/* $NetBSD: sctp6_usrreq.c,v 1.18 2019/02/24 07:20:33 maxv Exp $ */
+/* $NetBSD: sctp6_usrreq.c,v 1.19 2019/02/25 06:49:44 maxv Exp $ */
 
 /*
  * Copyright (c) 2001, 2002, 2003, 2004 Cisco Systems, Inc.
@@ -33,7 +33,7 @@
  * SUCH DAMAGE.
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sctp6_usrreq.c,v 1.18 2019/02/24 07:20:33 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sctp6_usrreq.c,v 1.19 2019/02/25 06:49:44 maxv Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -833,6 +833,9 @@ sctp6_send(struct socket *so, struct mbuf *m, struct sockaddr *nam,
 
 #ifdef INET
 	sin6 = (struct sockaddr_in6 *)nam;
+	/*
+	 * XXX XXX XXX Check sin6->sin6_len?
+	 */
 	if (inp6->in6p_flags & IN6P_IPV6_V6ONLY) {
 		/*
 		 * if IPV6_V6ONLY flag, we discard datagrams