bugfix: do not attempt to decode zero-length TLVs, only attempt to decode IS-REACH...

diff --git a/print-isoclns.c b/print-isoclns.c
index c001154783a95bd814a8058e6a4f4cc0987a7470..cfda033b7ace7392fd68f70d78dc0b32919e3c5f 100644 (file)
--- a/print-isoclns.c
+++ b/print-isoclns.c
@@ -26,7 +26,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/tcpdump/print-isoclns.c,v 1.106.2.6 2004-09-09 07:17:42 hannes Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/tcpdump/print-isoclns.c,v 1.106.2.7 2005-04-25 09:16:35 hannes Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -1506,6 +1506,9 @@ static int isis_print (const u_int8_t *p, u_int length)
                tlv_type,
                tlv_len);
 
+        if (tlv_len == 0) /* something is malformed */
+            break;
+
         /* now check if we have a decoder otherwise do a hexdump at the end*/
        switch (tlv_type) {
        case TLV_AREA_ADDR:
@@ -1536,7 +1539,7 @@ static int isis_print (const u_int8_t *p, u_int length)
            break;
 
         case TLV_ISNEIGH_VARLEN:
-            if (!TTEST2(*tptr, 1))
+            if (!TTEST2(*tptr, 1) && tmp > 1)
                goto trunctlv;
            lan_alen = *tptr++; /* LAN adress length */
             tmp --;