ethereal 0.10.6 (SVN 20040827090146)
Compiled with GTK+ 2.3.0, with GLib 2.3.5, with libpcap 0.8.3, with libz
1.1.4,
with libpcre 4.4, with Net-SNMP 5.1, with ADNS.
Running with libpcap version 0.8.3 on Linux 2.4.21.
I got this crash from both ethereal and tethereal. The attached pcap is
enough to trigger it. It does not happen with 0.10.5 (SVN
20040723183607) and the same versions of glib, gtk, libpcap, libz and ADNS.
==============
GLib-CRITICAL **: file gmem.c: line 746 (g_mem_chunk_alloc): assertion
`mem_chunk != NULL' failed
This partial trace is from "tethereal -r segv.pcap"
(process:18968): GLib-CRITICAL **: file gmem.c: line 746
(g_mem_chunk_alloc): assertion `mem_chunk != NULL' failed
Program received signal SIGSEGV, Segmentation fault.
get_tcp_conversation_data (pinfo=0x81e6ef0) at packet-tcp.c:293
293 tcpd->ual1=NULL;
(gdb) bt
#0 get_tcp_conversation_data (pinfo=0x81e6ef0) at packet-tcp.c:293
#1 0x404ab70a in verify_tcp_window_scaling (pinfo=0x81e6ef0) at
packet-tcp.c:502
Rest of backtrace seems irrelevent due to analysis below.
==============
It looks like get_tcp_conversation_data tries to use tcp_analysis_chunk
but tcp_analyze_seq_init did not initialise it because tcp_analyze_seq
was zero. The default value of tcp.analyze_sequence_numbers appears to
be FALSE which explains that.
So is the correct answer to check tcp_analyze_seq before calling
verify_tcp_window_scaling? That certainly fixes the crash.
Index: epan/dissectors/packet-tcp.c
===================================================================
--- epan/dissectors/packet-tcp.c (revision 11842)
+++ epan/dissectors/packet-tcp.c (working copy)
@@ -2893,7 +2893,8 @@
* then we should just forget about the windowscaling completely.
*/
if(!pinfo->fd->flags.visited){
- if((tcph->th_flags & (TH_SYN|TH_ACK))==(TH_SYN|TH_ACK)) {
+ if(tcp_analyze_seq &&
+ ((tcph->th_flags & (TH_SYN|TH_ACK))==(TH_SYN|TH_ACK))) {
verify_tcp_window_scaling(pinfo);
}
}
--
There's no point in being grown up if you can't be childish sometimes.
-- Dr. Who
Attachment:
segv.pcap
Description: Binary data
