Re: segfault in stream5

[Brett Edgar <brett.edgar () gmail com>]

I did a grep.  That function is not called (by that name) anywhere
else in the code.

Here's the backtrace:

Program received signal SIGSEGV, Segmentation fault.
Stream5GetApplicationData (ssnptr=0x5ea000005ea, protocol=5) at
spp_stream5.c:1368
1368    spp_stream5.c: No such file or directory.
        in spp_stream5.c
(gdb) bt
#0  Stream5GetApplicationData (ssnptr=0x5ea000005ea, protocol=5) at
spp_stream5.c:1368
#1  0x000000000046c4d5 in GetHttpSessionData (p=<value optimized out>)
at ./snort_httpinspect.h:163
#2  IsGzipData (p=<value optimized out>) at snort_httpinspect.c:3846
#3  0x000000000046c51a in GetHttpGzipData (data=0x5ea000005ea,
buf=0x5, len=0x7fffd61d95e8, type=0x7fffd61d95ec)
    at snort_httpinspect.c:3859
#4  0x0000000000449bc2 in AlertExtraData (ssnptr=0xf3e97f0,
data=<value optimized out>, log_funcs=<value optimized out>,
    log_func_count=<value optimized out>, event_id=2707977984,
event_second=4294967295) at spo_unified2.c:777
#5  0x0000000000491adf in purge_alerts (tcpssn=<value optimized out>,
talker=0x7fb5873e3160, listener=<value optimized out>,
    tdb=<value optimized out>, p=0x7fffd61d99f0) at snort_stream5_tcp.c:3211
#6  purge_to_seq (tcpssn=<value optimized out>, talker=0x7fb5873e3160,
listener=<value optimized out>,
    tdb=<value optimized out>, p=0x7fffd61d99f0) at snort_stream5_tcp.c:3304
#7  CheckFlushPolicyOnAck (tcpssn=<value optimized out>,
talker=0x7fb5873e3160, listener=<value optimized out>,
    tdb=<value optimized out>, p=0x7fffd61d99f0) at snort_stream5_tcp.c:9106
#8  0x000000000049598b in ProcessTcp (lwssn=0xf3e97f0,
p=0x7fffd61d99f0, tdb=<value optimized out>,
s5TcpPolicy=0x7fb57aaf3010)
    at snort_stream5_tcp.c:8684
#9  0x0000000000496178 in Stream5ProcessTcp (p=0x7fffd61d99f0,
lwssn=0xf3e97f0, s5TcpPolicy=0x7fb57aaf3010, skey=0x7fffd61d9920)
    at snort_stream5_tcp.c:5132
#10 0x000000000047a369 in Stream5Process (p=0x7fffd61d99f0,
context=<value optimized out>) at spp_stream5.c:1213
#11 0x0000000000431b85 in Preprocess (p=0x7fffd61d99f0) at detect.c:170
#12 0x0000000000426dee in ProcessPacket (user=<value optimized out>,
pkthdr=0x7fffd61da760, pkt=<value optimized out>, ft=0x0)
    at snort.c:1490
#13 0x000000000042adfa in PacketCallback (user=0x0,
pkthdr=0x7fffd61da760, pkt=0x7fb563769042 "") at snort.c:1404
#14 0x00007fb56a9045f3 in ?? () from /usr/lib/daq/daq_afpacket.so
#15 0x00000000004411f4 in DAQ_Acquire (max=<value optimized out>,
callback=0x7fffd61d95ec, user=0x7fb5a1687700 "") at sfdaq.c:464
#16 0x000000000042af8c in PacketLoop () at snort.c:2800
#17 0x000000000042c09f in SnortMain (argc=<value optimized out>,
argv=<value optimized out>) at snort.c:733
#18 0x000000000042c0e5 in main (argc=1514, argv=0x5) at snort.c:665


I'll work on getting a core dump and PCAP.  I do get full packet
capture, but I have yet to be able to reproduce the problem when
replaying the traffic...

-Brett

On Mon, Oct 3, 2011 at 9:59 PM, snort user <snort.user () gmail com> wrote:
> Hi Brett,
>
> Stream5GetApplicationData is called whenever an application needs to
> retrieve any information that it saved/piggybacked onto the session
> structure. You would see it in any of the preprocessors like dcerpc2
> or smtp. I am assuming that you would have done a grep by now to
> figure this out already.
>
> More importantly, would it be possible to provide
>
> 1. a stack trace ?
> 2. the core file ?
> 3. can you replicate the issue and if so can you capture the related
> pcap when the issue occur ?
>
> These would be a great start to debug the issue and the list,
> including me, would be able to help you out as well.
>
>
> cheers
>
>
>
>
>
> On Mon, Oct 3, 2011 at 10:46 PM, Brett Edgar <brett.edgar () gmail com> wrote:
> > I am getting segfaults in spp_stream5.c on line 1368 and it's
> > happening on multiple systems that have completely disjoint network
> > traffic.  Somehow, the ssn pointer being passed into stream5 is not
> > NULL (otherwise the if(ssnptr) would prevent the crash) but also not
> > valid (since I'm getting a segfault).
> >
> > The systems that are exhibiting the problem are Gentoo systems.  Some
> > are x86 and some are amd64.  The stream5 configurations are very
> > similar between the systems.  Here is the stream5 configuration on one
> > of the systems:
> >
> > preprocessor stream5_global: track_tcp yes, \
> >   track_udp yes, \
> >   track_icmp no, \
> >   max_tcp 262144, \
> >   max_udp 131072
> > preprocessor stream5_tcp: policy windows, require_3whs 180, \
> >   overlap_limit 10, small_segments 3 bytes 150, timeout 180, \
> >    ports client 21 22 23 25 42 53 79 109 110 111 113 119 135 136 137 139 143 \
> >        161 445 513 514 587 593 691 1433 1521 2100 3306 6070 6665 6666
> > 6667 6668 6669 \
> >        7000 8181 32770 32771 32772 32773 32774 32775 32776 32777 32778 32779, \
> >    ports both 80 81 110 143 311 443 465 563 591 593 636 901 989 992
> > 993 994 995 1220 1414 1830 2301 2381 2809 3128 3702 4343 5250 7907
> > 7001 7145 7510 7802 7777 7779 \
> >        7801 7900 7901 7902 7903 7904 7905 7906 7908 7909 7910 7911
> > 7912 7913 7914 7915 7916 \
> >        7917 7918 7919 7920 8000 8008 8014 8028 8080 8088 8118 8123
> > 8180 8243 8280 8800 8888 8899 9080 9090 9091 9443 9999 11371 55555
> > preprocessor stream5_udp: timeout 180
> >
> > That's very close, if not identical to, the snort.conf  in the VRT
> > tarballs (except for the active response configuration statements in
> > stream5_global that are not enabled because I didn't compile snort
> > with that configuration option).
> >
> > I am a fairly competent C programmer, but I'm asking for suggestions
> > on where to look in this mailing list since I am not familiar with the
> > Snort code.  I'm hoping someone knows when Stream5GetApplicationData
> > (the function that contains the segfault) gets called so I can narrow
> > down my search more quickly...
> >
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definitive record of customers, application performance, security
threats, fraudulent activity and more. Splunk takes this data and makes
sense of it. Business sense. IT sense. Common sense.
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