Upgrade to tcpdump 4.9.2.

From CHANGES:

  Sunday September 3, 2017 denis@ovsienko.info
  Summary for 4.9.2 tcpdump release
    Do not use getprotobynumber() for protocol name resolution.  Do not do
      any protocol name resolution if -n is specified.
    Improve errors detection in the test scripts.
    Fix a segfault with OpenSSL 1.1 and improve OpenSSL usage.
    Clean up IS-IS printing.
    Fix buffer overflow vulnerabilities:
      CVE-2017-11543 (SLIP)
      CVE-2017-13011 (bittok2str_internal)
    Fix infinite loop vulnerabilities:
      CVE-2017-12989 (RESP)
      CVE-2017-12990 (ISAKMP)
      CVE-2017-12995 (DNS)
      CVE-2017-12997 (LLDP)
    Fix buffer over-read vulnerabilities:
      CVE-2017-11541 (safeputs)
      CVE-2017-11542 (PIMv1)
      CVE-2017-12893 (SMB/CIFS)
      CVE-2017-12894 (lookup_bytestring)
      CVE-2017-12895 (ICMP)
      CVE-2017-12896 (ISAKMP)
      CVE-2017-12897 (ISO CLNS)
      CVE-2017-12898 (NFS)
      CVE-2017-12899 (DECnet)
      CVE-2017-12900 (tok2strbuf)
      CVE-2017-12901 (EIGRP)
      CVE-2017-12902 (Zephyr)
      CVE-2017-12985 (IPv6)
      CVE-2017-12986 (IPv6 routing headers)
      CVE-2017-12987 (IEEE 802.11)
      CVE-2017-12988 (telnet)
      CVE-2017-12991 (BGP)
      CVE-2017-12992 (RIPng)
      CVE-2017-12993 (Juniper)
      CVE-2017-11542 (PIMv1)
      CVE-2017-11541 (safeputs)
      CVE-2017-12994 (BGP)
      CVE-2017-12996 (PIMv2)
      CVE-2017-12998 (ISO IS-IS)
      CVE-2017-12999 (ISO IS-IS)
      CVE-2017-13000 (IEEE 802.15.4)
      CVE-2017-13001 (NFS)
      CVE-2017-13002 (AODV)
      CVE-2017-13003 (LMP)
      CVE-2017-13004 (Juniper)
      CVE-2017-13005 (NFS)
      CVE-2017-13006 (L2TP)
      CVE-2017-13007 (Apple PKTAP)
      CVE-2017-13008 (IEEE 802.11)
      CVE-2017-13009 (IPv6 mobility)
      CVE-2017-13010 (BEEP)
      CVE-2017-13012 (ICMP)
      CVE-2017-13013 (ARP)
      CVE-2017-13014 (White Board)
      CVE-2017-13015 (EAP)
      CVE-2017-11543 (SLIP)
      CVE-2017-13016 (ISO ES-IS)
      CVE-2017-13017 (DHCPv6)
      CVE-2017-13018 (PGM)
      CVE-2017-13019 (PGM)
      CVE-2017-13020 (VTP)
      CVE-2017-13021 (ICMPv6)
      CVE-2017-13022 (IP)
      CVE-2017-13023 (IPv6 mobility)
      CVE-2017-13024 (IPv6 mobility)
      CVE-2017-13025 (IPv6 mobility)
      CVE-2017-13026 (ISO IS-IS)
      CVE-2017-13027 (LLDP)
      CVE-2017-13028 (BOOTP)
      CVE-2017-13029 (PPP)
      CVE-2017-13030 (PIM)
      CVE-2017-13031 (IPv6 fragmentation header)
      CVE-2017-13032 (RADIUS)
      CVE-2017-13033 (VTP)
      CVE-2017-13034 (PGM)
      CVE-2017-13035 (ISO IS-IS)
      CVE-2017-13036 (OSPFv3)
      CVE-2017-13037 (IP)
      CVE-2017-13038 (PPP)
      CVE-2017-13039 (ISAKMP)
      CVE-2017-13040 (MPTCP)
      CVE-2017-13041 (ICMPv6)
      CVE-2017-13042 (HNCP)
      CVE-2017-13043 (BGP)
      CVE-2017-13044 (HNCP)
      CVE-2017-13045 (VQP)
      CVE-2017-13046 (BGP)
      CVE-2017-13047 (ISO ES-IS)
      CVE-2017-13048 (RSVP)
      CVE-2017-13049 (Rx)
      CVE-2017-13050 (RPKI-Router)
      CVE-2017-13051 (RSVP)
      CVE-2017-13052 (CFM)
      CVE-2017-13053 (BGP)
      CVE-2017-13054 (LLDP)
      CVE-2017-13055 (ISO IS-IS)
      CVE-2017-13687 (Cisco HDLC)
      CVE-2017-13688 (OLSR)
      CVE-2017-13689 (IKEv1)
      CVE-2017-13690 (IKEv2)
      CVE-2017-13725 (IPv6 routing headers)

Bug: N/A
Test: ran manually
Change-Id: I6fbfa46046ee89d40d13024777e27623a23cb258
diff --git a/print-chdlc.c b/print-chdlc.c
index 450d286..24acfbd 100644
--- a/print-chdlc.c
+++ b/print-chdlc.c
@@ -46,21 +46,18 @@
 u_int
 chdlc_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, register const u_char *p)
 {
-	register u_int length = h->len;
-	register u_int caplen = h->caplen;
-
-	if (caplen < CHDLC_HDRLEN) {
-		ND_PRINT((ndo, "[|chdlc]"));
-		return (caplen);
-	}
-        return (chdlc_print(ndo, p,length));
+	return chdlc_print(ndo, p, h->len);
 }
 
 u_int
 chdlc_print(netdissect_options *ndo, register const u_char *p, u_int length)
 {
 	u_int proto;
+	const u_char *bp = p;
 
+	if (length < CHDLC_HDRLEN)
+		goto trunc;
+	ND_TCHECK2(*p, CHDLC_HDRLEN);
 	proto = EXTRACT_16BITS(&p[2]);
 	if (ndo->ndo_eflag) {
                 ND_PRINT((ndo, "%s, ethertype %s (0x%04x), length %u: ",
@@ -94,12 +91,15 @@
 		break;
         case ETHERTYPE_ISO:
                 /* is the fudge byte set ? lets verify by spotting ISO headers */
+                if (length < 2)
+                    goto trunc;
+                ND_TCHECK_16BITS(p);
                 if (*(p+1) == 0x81 ||
                     *(p+1) == 0x82 ||
                     *(p+1) == 0x83)
-                    isoclns_print(ndo, p + 1, length - 1, ndo->ndo_snapend - p - 1);
+                    isoclns_print(ndo, p + 1, length - 1);
                 else
-                    isoclns_print(ndo, p, length, ndo->ndo_snapend - p);
+                    isoclns_print(ndo, p, length);
                 break;
 	default:
                 if (!ndo->ndo_eflag)
@@ -108,6 +108,10 @@
 	}
 
 	return (CHDLC_HDRLEN);
+
+trunc:
+	ND_PRINT((ndo, "[|chdlc]"));
+	return ndo->ndo_snapend - bp;
 }
 
 /*