[src/trunk]: src/sys/netipsec Make sure the Authentication Header fits the mb...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/50fbaa92a46f
branches:  trunk
changeset: 829854:50fbaa92a46f
user:      maxv <maxv%NetBSD.org@localhost>
date:      Thu Feb 15 07:38:46 2018 +0000

description:
Make sure the Authentication Header fits the mbuf chain, otherwise panic.

diffstat:

 sys/netipsec/xform_ah.c |  15 +++++++++++++--
 1 files changed, 13 insertions(+), 2 deletions(-)

diffs (36 lines):

diff -r 3ae013e09578 -r 50fbaa92a46f sys/netipsec/xform_ah.c
--- a/sys/netipsec/xform_ah.c   Thu Feb 15 07:16:05 2018 +0000
+++ b/sys/netipsec/xform_ah.c   Thu Feb 15 07:38:46 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: xform_ah.c,v 1.80 2018/02/15 07:16:05 maxv Exp $       */
+/*     $NetBSD: xform_ah.c,v 1.81 2018/02/15 07:38:46 maxv Exp $       */
 /*     $FreeBSD: src/sys/netipsec/xform_ah.c,v 1.1.4.1 2003/01/24 05:11:36 sam Exp $   */
 /*     $OpenBSD: ip_ah.c,v 1.63 2001/06/26 06:18:58 angelos Exp $ */
 /*
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xform_ah.c,v 1.80 2018/02/15 07:16:05 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xform_ah.c,v 1.81 2018/02/15 07:38:46 maxv Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_inet.h"
@@ -670,6 +670,17 @@
                error = EACCES;
                goto bad;
        }
+       if (skip + authsize + rplen > m->m_pkthdr.len) {
+               char buf[IPSEC_ADDRSTRLEN];
+               DPRINTF(("%s: bad mbuf length %u (expecting >= %lu)"
+                       " for packet in SA %s/%08lx\n", __func__,
+                       m->m_pkthdr.len, (u_long)(skip + authsize + rplen),
+                       ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
+                       (u_long) ntohl(sav->spi)));
+               stat = AH_STAT_BADAUTHL;
+               error = EACCES;
+               goto bad;
+       }
 
        AH_STATADD(AH_STAT_IBYTES, m->m_pkthdr.len - skip - hl);