From: Michael Richardson <mcr@sandelman.ca>
Date: Fri, 16 Aug 2019 20:13:25 +0000 (-0400)
Subject: guard against tlen becoming very large from subtraction
X-Git-Tag: tcpdump-4.9.3~51
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/d330c27e8559e78b4d4fa69175edb051ac40073e?hp=3bc3e93dfe7415e1eb176b3b809dfd4d6f836e75

guard against tlen becoming very large from subtraction
---

diff --git a/print-sflow.c b/print-sflow.c
index b78fa473..dcaf28e8 100644
--- a/print-sflow.c
+++ b/print-sflow.c
@@ -924,6 +924,8 @@ sflow_print(netdissect_options *ndo,
 
     /* skip Common header */
     tptr += sizeof(const struct sflow_datagram_t);
+
+    if(tlen <= sizeof(const struct sflow_datagram_t)) goto trunc;
     tlen -= sizeof(const struct sflow_datagram_t);
 
     while (nsamples > 0 && tlen > 0) {