Wireshark-bugs: [Wireshark-bugs] [Bug 6076] New: sflow dissector bug while parsing extended swit
Date: Thu, 30 Jun 2011 03:19:30 -0700 (PDT)
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=6076

           Summary: sflow dissector bug while parsing extended switch data
           Product: Wireshark
           Version: 1.4.6
          Platform: All
        OS/Version: Windows Vista
            Status: NEW
          Severity: Major
          Priority: Low
         Component: Wireshark
        AssignedTo: [email protected]
        ReportedBy: [email protected]


Created an attachment (id=6591)
 --> (https://bugs.wireshark.org/bugzilla/attachment.cgi?id=6591)
pcap capture containing parsing error

Build Information:
Version 1.4.6 (SVN Rev 36706 from /trunk-1.4)

Copyright 1998-2011 Gerald Combs <[email protected]> and contributors.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Compiled (32-bit) with GTK+ 2.16.6, with GLib 2.22.4, with WinPcap (version
unknown), with libz 1.2.3, without POSIX capabilities, without libpcre, with
SMI
0.4.8, with c-ares 1.7.1, with Lua 5.1, without Python, with GnuTLS 2.10.3,
with
Gcrypt 1.4.6, with MIT Kerberos, with GeoIP, with PortAudio V19-devel (built
Apr
18 2011), with AirPcap.

Running on 32-bit Windows Vista Service Pack 2, build 6002, with WinPcap
version
4.1.2 (packet.dll version 4.1.0.2001), based on libpcap version 1.0 branch
1_0_rel0b (20091008), GnuTLS 2.10.3, Gcrypt 1.4.6, without AirPcap.

Built using Microsoft Visual C++ 9.0 build 21022

Wireshark is Open Source Software released under the GNU General Public
License.

Check the man page and http://www.wireshark.org for more information.
--
wireshark seems to hit a parsing error while parsing "Flow Samples" which
contains "Extended Switch Data". Normal flow sample are parsed fine, so are
counter samples.

Using Inmon's "sflowtool" exe, I am able to parse the sflow packet without any
errors.
Output of "sflowtool -r ../sflow_ta2.pcap -l

pcap_timestamp = Thu Jun  2 22:58:33 2011

FLOW,192.168.1.2,114,1073741823,0050569f3154,1cc1de4d444b,0x0800,10,10,192.168.1.4,192.168.1.2,1,0x00,128,3,3,0x00,194,176,50
CNTR,192.168.1.2,4,6,10000000,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0
CNTR,192.168.1.2,20,6,10000000,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0
CNTR,192.168.1.2,76,6,10000000,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0
CNTR,192.168.1.2,81,6,10000000,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0
CNTR,192.168.1.2,88,6,10000000,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0
CNTR,192.168.1.2,92,6,10000000,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0

Attached is the pcap capture(sflow sequence number 38 is the culprit packet).

Error is:
Dissector bug, protocol sFlow: proto.c:3711: failed assertion "end>= fi->start"

Please fix this, ot let us know if there is something wrong in the sflow packet
itself(sflowtool working properly seems to suggest it's a dissector bug). 

Thanks and Regards,
Subin

-- 
Configure bugmail: https://bugs.wireshark.org/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are watching all bug changes.