--- /dev/null
+--- a/print-ppp.c
++++ b/print-ppp.c
+@@ -1368,19 +1368,29 @@ trunc:
+ }
+
+ #ifndef TCPDUMP_MINI
++/*
++ * Un-escape RFC 1662 PPP in HDLC-like framing, with octet escapes.
++ * The length argument is the on-the-wire length, not the captured
++ * length; we can only un-escape the captured part.
++ */
+ static void
+ ppp_hdlc(netdissect_options *ndo,
+ const u_char *p, int length)
+ {
++ u_int caplen = ndo->ndo_snapend - p;
+ u_char *b, *t, c;
+ const u_char *s;
+- int i, proto;
++ u_int i;
++ int proto;
+ const void *se;
+
++ if (caplen == 0)
++ return;
++
+ if (length <= 0)
+ return;
+
+- b = (u_char *)malloc(length);
++ b = (u_char *)malloc(caplen);
+ if (b == NULL)
+ return;
+
+@@ -1389,10 +1399,10 @@ ppp_hdlc(netdissect_options *ndo,
+ * Do this so that we dont overwrite the original packet
+ * contents.
+ */
+- for (s = p, t = b, i = length; i > 0 && ND_TTEST(*s); i--) {
++ for (s = p, t = b, i = caplen; i != 0; i--) {
+ c = *s++;
+ if (c == 0x7d) {
+- if (i <= 1 || !ND_TTEST(*s))
++ if (i <= 1)
+ break;
+ i--;
+ c = *s++ ^ 0x20;