# [SR-Users] kamailio 4.4.1 crash on bad sip response

David Escartín Almudévar descartin at bts.io
Tue Mar 28 13:42:23 CEST 2017

```hello Daniel

thanks a lot.
we actually will start testing 5.0 to migrate to it, but in the meantime
it's great if we can patch it on the 4.4

best regards
david

El mar, 28-03-2017 a las 13:37 +0200, Daniel-Constantin Mierla escribió:

> Hello,
>
> I pushed a safety checks to avoid crash in this situation. I will have
> to investigate deeper why it got to this state, but for now the fix
> should avoid this crash in a similar situation. You have to use the
> latest branch 4.4 or backport the patch
>
> Cheers,
> Daniel
>
>
>
>
> On 28/03/2017 12:15, David Escartín Almudévar wrote:
>
> >
> > hello Daniel
> >
> > it happened only once as far as i know, i tried to duplicate by
> > myself but i couldnt create the sipp scenario
> > i will try to duplicate it setting the octal parameters in hex
> > escaped by % in the SIP uris to see if i can, but i didnt have time
> > yet
> >
> > in the meantime here you have the information
> >
> > (gdb) frame 6
> > #6  0x00000000004696c4 in dns_srv_sip_resolvehost
> > (name=0x7f6906943188, port=0x7fff120795e2, proto=0x7fff120795e1
> > "\001\330\023") at dns_cache.c:2679
> > 2679 he=dns_get_he(name, dns_flags);
> > (gdb) p *name
> > \$1 = {s = 0x0, len = 0}
> > (gdb) p *port
> > \$2 = 5080
> >
> > thanks a lot and regards
> > david
> >
> >
> >
> > El lun, 27-03-2017 a las 21:04 +0200, Daniel-Constantin Mierla
> > escribió:
> >
> > > Hello,
> > >
> > > did it happen only once, or it can be reproduced?
> > >
> > > Can you also get from gdb:
> > >
> > > frame 6
> > >
> > > p *name
> > >
> > > p *port
> > >
> > >
> > > Cheers,
> > > Daniel
> > >
> > >
> > >
> > > On 27/03/2017 16:43, David Escartín Almudévar wrote:
> > >
> > >
> > > > hello Daniel
> > > >
> > > > here you have
> > > >
> > > > (gdb) frame 1
> > > > #1  0x000000000045b472 in _dns_hash_find (name=0x7f6906943188,
> > > > type=1, h=0x7fff120793cc, err=0x7fff120793ac) at dns_cache.c:535
> > > > 535 *h=dns_hash_no(name->s, name->len, type);
> > > > (gdb) info locals
> > > > e = 0x7f69069015b8
> > > > tmp = 0x7f69069247e0
> > > > ret = 0x0
> > > > now = 689922868
> > > > cname_chain = 0
> > > > cname = {s = 0xab0e93 "Via: SIP/2.0/UDP \020?\337\v\234\262\264
> > > > \016 :5080;received=;rport=5080;branch=\020?\337\v\234\262\264
> > > > \016 \r\nContent-Length: 0\r\n\r\n", len = 11210375}
> > > > __FUNCTION__ = "_dns_hash_find"
> > > > (gdb) list
> > > > 530 cname_chain=0;
> > > > 531 ret=0;
> > > > 532 now=get_ticks_raw();
> > > > 533 *err=0;
> > > > 534 again:
> > > > 535 *h=dns_hash_no(name->s, name->len, type);
> > > > 536 #ifdef DNS_CACHE_DEBUG
> > > > 537 LM_DBG("(%.*s(%d), %d), h=%d\n", name->len, name->s,
> > > > name->len, type, *h);
> > > > 538 #endif
> > > > 539 clist_foreach_safe(&dns_hash[*h], e, tmp, next){
> > > >
> > > >
> > > >
> > > > thanks a lot and regards
> > > > david
> > > >
> > > >
> > > >
> > > >
> > > > El lun, 27-03-2017 a las 13:54 +0200, Daniel-Constantin Mierla
> > > > escribió:
> > > >
> > > > > Hello,
> > > > >
> > > > > the backtrace is no longer matching the 4.4 branch code, as
> > > > > you run an older release in that series.
> > > > >
> > > > > Can you get with gdb from the core the output of the following
> > > > > commands:
> > > > >
> > > > > frame 1
> > > > >
> > > > > info locals
> > > > >
> > > > > list
> > > > >
> > > > >
> > > > > and send them here on the mailing list.
> > > > >
> > > > > Cheers,
> > > > > Daniel
> > > > >
> > > > > On 24/03/2017 14:50, David Escartín Almudévar wrote:
> > > > >
> > > > >
> > > > > > hello all, Daniel
> > > > > >
> > > > > > checking the core with the gdb, we have checked the
> > > > > > variables at the frames of the backtrace, to try to get the
> > > > > > full sip message seems it seemed truncated.
> > > > > > checking the buf variable of the frame 11 which theorically
> > > > > > contains the sip msg to parse we have the string
> > > > > >
> > > > > >
> > > > > > SIP/2.0 487 Request Terminated\r\nFrom: \"881237046977
> > > > > > \"<sip:881237046977 at 79.170.68.185;user=phone>;tag=B7jgc8jQ4m5pB\r\nTo: <sip:5926053324 at 79.170.68.186:5060>;tag=e0d50be-13c4-58d47cba-a2ed9808-36fa\r\nl\337K\016\213\347: \344\003\r\nCSeq: 104824272 INVITE\r\nVia: SIP/2.0/UDP L\263\264\016\020?\337\v\234\262\264\016 ;branch=\327\f\340\r\nVia: SIP/2.0/UDP \020?\337\v\234\262\264\016 :5080;received=;rport=5080;branch=\020?\337\v\234\262\264\016 \r\nContent-Length: 0\r\n\r\n
> > > > > >
> > > > > > this is i guess how gdb parses the message, so i guess i
> > > > > > cannot introduce this like that in a xml sipp formal, since
> > > > > > CRLF is represented as \r\n, so others parts like l\337K\016
> > > > > > \213\347: \344\003 i have no idea what they are, because
> > > > > > they also seem to be out of the ASCII table ¿?
> > > > > > anycase, seems the message is very bad formed, and the
> > > > > > kamailio tries to resolve the host of the Via and it gets
> > > > > > nothing, so the function get_hash1_case_raw is fed by a nul
> > > > > > value and seems that the reason it crashes
> > > > > >
> > > > > > hope you can retrieve information from that message to find
> > > > > > out what kind of message it exactly is and see if it's
> > > > > > possible to avoid kamailio's crash in this scenario
> > > > > >
> > > > > >
> > > > > > best regards
> > > > > > david
> > > > > >
> > > > > >
> > > > > >
> > > > > > El vie, 24-03-2017 a las 12:10 +0100, David Escartín
> > > > > > Almudévar escribió:
> > > > > >
> > > > > > > hello all
> > > > > > >
> > > > > > > we have experienced a crash and tracing the logs and the
> > > > > > > core, seems it was because a sip response from an
> > > > > > > endpoint.
> > > > > > > a UDP receiver (26248) crashed and the last message we see
> > > > > > > on it is a 487 quite bad formed
> > > > > > >
> > > > > > > Mar 24 01:58:02
> > > > > > > mia-proxy-inout-1-stby /usr/local/kamailio/sbin/kamailio[26248]: ERROR: tm [t_lookup.c:1055]: t_check_msg(): ERROR: reply doesn't have a via, cseq or call-id header
> > > > > > > Mar 24 01:58:17
> > > > > > > mia-proxy-inout-1-stby /usr/local/kamailio/sbin/kamailio[26230]: ALERT: <core> [main.c:739]: handle_sigs(): child process 26248 exited by a signal 11
> > > > > > >
> > > > > > >
> > > > > > > the backtrace of the core
> > > > > > > (gdb) backtrace
> > > > > > > #0  0x0000000000457ab9 in get_hash1_case_raw (s=0x0,
> > > > > > > len=0) at hashes.h:210
> > > > > > > #1  0x000000000045b472 in _dns_hash_find
> > > > > > > (name=0x7f6906943188, type=1, h=0x7fff120793cc,
> > > > > > > err=0x7fff120793ac) at dns_cache.c:535
> > > > > > > #2  0x0000000000461285 in dns_hash_get
> > > > > > > (name=0x7f6906943188, type=1, h=0x7fff120793cc,
> > > > > > > err=0x7fff120793ac) at dns_cache.c:762
> > > > > > > #3  0x0000000000467194 in dns_get_entry
> > > > > > > (name=0x7f6906943188, type=1) at dns_cache.c:2102
> > > > > > > #4  0x0000000000468a05 in dns_a_get_he
> > > > > > > (name=0x7f6906943188) at dns_cache.c:2432
> > > > > > > #5  0x0000000000468bb9 in dns_get_he (name=0x7f6906943188,
> > > > > > > flags=1) at dns_cache.c:2505
> > > > > > > #6  0x00000000004696c4 in dns_srv_sip_resolvehost
> > > > > > > (name=0x7f6906943188, port=0x7fff120795e2,
> > > > > > > proto=0x7fff120795e1 "\001\330\023") at dns_cache.c:2679
> > > > > > > #7  0x000000000046aa37 in dns_sip_resolvehost
> > > > > > > (name=0x7f6906943188, port=0x7fff120795e2,
> > > > > > > proto=0x7fff120795e1 "\001\330\023") at dns_cache.c:2849
> > > > > > > #8  0x000000000049519e in update_sock_struct_from_via
> > > > > > > (to=0x7fff12079708, msg=0x7f69069a1dd8,
> > > > > > > via=0x7f69068f82a8) at forward.c:704
> > > > > > > #9  0x0000000000495ee5 in do_forward_reply
> > > > > > > (msg=0x7f69069a1dd8, mode=0) at forward.c:766
> > > > > > > #10 0x00000000004970af in forward_reply
> > > > > > > (msg=0x7f69069a1dd8) at forward.c:849
> > > > > > > #11 0x00000000005197ef in receive_msg (
> > > > > > >     buf=0xab0d80 "SIP/2.0 487 Request Terminated\r\nFrom:
> > > > > > > \"8888888888
> > > > > > > \"<sip:8888888888 at 7.7.7.7;user=phone>;tag=B7jgc8jQ4m5pB\r
> > > > > > > \nTo:
> > > > > > > <sip:555555555 at 8.8.8.8:5060>;tag=e0d50be-13c4-58d47cba-a2ed9808-36fa\r\nl\337K\016"..., len=367, rcv_info=0x7fff12079a10) at receive.c:299
> > > > > > > #12 0x0000000000627b43 in udp_rcv_loop () at
> > > > > > > udp_server.c:495
> > > > > > > #13 0x00000000004b107a in main_loop () at main.c:1600
> > > > > > > #14 0x00000000004b842f in main (argc=13,
> > > > > > > argv=0x7fff12079fb8) at main.c:2616
> > > > > > >
> > > > > > >
> > > > > > > i have tried to duplicate the issue, but i dont know how
> > > > > > > to translate l\337K\016 to a xml notation
> > > > > > > i guess this is some weird that cannot be processed for
> > > > > > > kamailio
> > > > > > >
> > > > > > > could you please take a look and let me know if you know
> > > > > > > how to duplicate and fix this crash?
> > > > > > >
> > > > > > > thanks a lot and regards
> > > > > > > david
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > _______________________________________________
> > > > > > SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
> > > > > > sr-users at lists.sip-router.org
> > > > > > http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
> > > > >
> > > > >
> > > > >
> > > > > --
> > > > > Daniel-Constantin Mierla
> > > > > Kamailio Advanced Training - Mar 6-8 (Europe) and Mar 20-22 (USA) - www.asipto.com
> > > > > Kamailio World Conference - May 8-10, 2017 - www.kamailioworld.com
> > > > > _______________________________________________
> > > > > SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
> > > > > sr-users at lists.sip-router.org
> > > > > http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
> > > >
> > > >
> > >
> > >
> > >
> > > --
> > > Daniel-Constantin Mierla
> > > Kamailio Advanced Training - Mar 6-8 (Europe) and Mar 20-22 (USA) - www.asipto.com
> > > Kamailio World Conference - May 8-10, 2017 - www.kamailioworld.com
> >
> >
>
>
>
> --
> Daniel-Constantin Mierla