Fix fuzz failure reported in https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=7566 :

Don't try to reassemble a message of length 0 (fixes a later divide-by-zero
error but I don't see why we'd want to do any work for message whose length
we think is 0).

svn path=/trunk/; revision=44247

1 files changed, 4 insertions, 5 deletions

diff --git a/epan/dissectors/packet-dcp-etsi.c b/epan/dissectors/packet-dcp-etsi.c
index f33d28fc6e..cacafdaaf3 100644
--- a/epan/dissectors/packet-dcp-etsi.c
+++ b/epan/dissectors/packet-dcp-etsi.c
@@ -511,14 +511,13 @@ dissect_pft(tvbuff_t * tvb, packet_info * pinfo, proto_tree * tree)
     gboolean save_fragmented = pinfo->fragmented;
     guint16 real_len = tvb_length(tvb)-offset;
     proto_tree_add_item (pft_tree, hf_edcp_pft_payload, tvb, offset, real_len, ENC_NA);
-    if(real_len != payload_len) {
+    if(real_len != payload_len || real_len == 0) {
       if(li)
         proto_item_append_text(li, " (length error (%d))", real_len);
     }
-    next_tvb = dissect_pft_fragmented(tvb, pinfo, pft_tree,
-                                      findex, fcount, seq, offset, real_len,
-                                      fec, rsk, rsz
-                                      );
+    if (real_len)
+      next_tvb = dissect_pft_fragmented(tvb, pinfo, pft_tree, findex, fcount,
+                                        seq, offset, real_len, fec, rsk, rsz);
     pinfo->fragmented = save_fragmented;
   } else {
     next_tvb = tvb_new_subset_remaining (tvb, offset);