[sr-dev] Crash bug freeing To headers

Alex Balashov abalashov at evaristesys.com
Wed Aug 28 09:11:06 CEST 2013 

With the patch applied, I sometimes get this crash, too:

(gdb) where
#0  0x0000000000539ed9 in qm_detach_free (qm=0x7f516c197010,
     frag=0x7f516c3b6dc0) at mem/q_malloc.c:268
#1  0x000000000053a118 in qm_malloc (qm=0x7f516c197010, size=960)
     at mem/q_malloc.c:386
#2  0x00000000004bc41d in rval_new_empty (extra_size=102) at rvalue.c:236
#3  0x00000000004bc48f in rval_new_str (s=0x7ffff3194e70, extra_size=80)
     at rvalue.c:260
#4  0x00000000004beb87 in rval_convert (h=0x7ffff3196cb0, 
msg=0x7f516b6e7920,
     type=RV_STR, v=0x7f516c2e3728, c=0x7ffff3195030) at rvalue.c:1321
#5  0x00000000004c002b in rval_str_lop2 (h=0x7ffff3196cb0, 
msg=0x7f516b6e7920,
     res=0x7ffff31954d8, op=RVE_EQ_OP, l=0x7f516c2e3728, c1=0x7ffff3195030,
     r=0x7f516c2e3ea8, c2=0x0) at rvalue.c:1752
#6  0x00000000004c0c61 in rval_expr_eval_int (h=0x7ffff3196cb0,
     msg=0x7f516b6e7920, res=0x7ffff31954d8, rve=0x7f516c2e4580)
     at rvalue.c:2058
#7  0x0000000000418d5a in do_action (h=0x7ffff3196cb0, a=0x7f516c2e59d0,
     msg=0x7f516b6e7920) at action.c:1050
#8  0x0000000000421aa7 in run_actions (h=0x7ffff3196cb0, a=0x7f516c2e3580,
     msg=0x7f516b6e7920) at action.c:1573
#9  0x000000000042047f in do_action (h=0x7ffff3196cb0, a=0x7f516c2e5d70,
     msg=0x7f516b6e7920) at action.c:1374
#10 0x0000000000421aa7 in run_actions (h=0x7ffff3196cb0, a=0x7f516c2daae0,
     msg=0x7f516b6e7920) at action.c:1573
#11 0x0000000000418fa2 in do_action (h=0x7ffff3196cb0, a=0x7f516c2eb450,
     msg=0x7f516b6e7920) at action.c:1065
#12 0x0000000000421aa7 in run_actions (h=0x7ffff3196cb0, a=0x7f516c2eb450,
     msg=0x7f516b6e7920) at action.c:1573
#13 0x0000000000418ffb in do_action (h=0x7ffff3196cb0, a=0x7f516c2eb550,
     msg=0x7f516b6e7920) at action.c:1069
#14 0x0000000000421aa7 in run_actions (h=0x7ffff3196cb0, a=0x7f516c2c4170,
     msg=0x7f516b6e7920) at action.c:1573
#15 0x0000000000416f3a in do_action (h=0x7ffff3196cb0, a=0x7f516c2f5800,
---Type <return> to continue, or q <return> to quit---
     msg=0x7f516b6e7920) at action.c:690
#16 0x0000000000421aa7 in run_actions (h=0x7ffff3196cb0, a=0x7f516c2ef330,
     msg=0x7f516b6e7920) at action.c:1573
#17 0x0000000000422231 in run_top_route (a=0x7f516c2ef330, 
msg=0x7f516b6e7920,
     c=0x0) at action.c:1658
#18 0x00007f516b49b220 in run_failure_handlers (t=0x7f506769a3b0,
     rpl=0x7f516c3b5df0, code=480, extra_flags=64) at t_reply.c:1024
#19 0x00007f516b49c39b in t_should_relay_response (Trans=0x7f506769a3b0,
     new_code=480, branch=0, should_store=0x7ffff3196f90,
     should_relay=0x7ffff3196f94, cancel_data=0x7ffff31971a0,
     reply=0x7f516c3b5df0) at t_reply.c:1300
#20 0x00007f516b49dec4 in relay_reply (t=0x7f506769a3b0, 
p_msg=0x7f516c3b5df0,
     branch=0, msg_status=480, cancel_data=0x7ffff31971a0, do_put_on_wait=1)
     at t_reply.c:1703
#21 0x00007f516b4a0f46 in reply_received (p_msg=0x7f516c3b5df0)
     at t_reply.c:2370
#22 0x0000000000458861 in do_forward_reply (msg=0x7f516c3b5df0, mode=0)
     at forward.c:799
#23 0x00000000004590d0 in forward_reply (msg=0x7f516c3b5df0) at 
forward.c:882
#24 0x000000000049e276 in receive_msg (
     buf=0x9065c0 "SIP/2.0 480 Temporarily Unavailable\r\nVia: 
SIP/2.0/UDP 55.177.31.199;branch=z9hG4bK25c.fe28da07.0\r\nVia: 
SIP/2.0/UDP 
192.13.219.87:5060;branch=z9hG4bK-1cc0-521da21e-332440e0-d482ab\r\nRecord-Route: 
<sip:6"..., len=862,
     rcv_info=0x7ffff3197520) at receive.c:272
#25 0x000000000052ffa1 in udp_rcv_loop () at udp_server.c:557
#26 0x0000000000467de2 in main_loop () at main.c:1638
#27 0x000000000046ad8b in main (argc=13, argv=0x7ffff3197858) at main.c:2566

I've seen it before in this scenario, but so infrequently that I didn't 
think it was worth mentioning.

On 08/28/2013 03:01 AM, Alex Balashov wrote:

> Hi Daniel,
>
> With your patch applied (setting param list head to NULL), it now
> crashes in a different place:
>
> Program terminated with signal 11, Segmentation fault.
> #0  0x000000000055e602 in free_to_params (tb=0x7f31fee421a0)
>      at parser/parse_to.c:827
> 827            foo = tp->next;
> Missing separate debuginfos, use: debuginfo-install
> cyrus-sasl-lib-2.1.23-13.el6_3.1.x86_64 glibc-2.12-1.107.el6.x86_64
> keyutils-libs-1.4-4.el6.x86_64 krb5-libs-1.10.3-10.el6_4.2.x86_64
> libcom_err-1.41.12-14.el6.x86_64 libselinux-2.0.94-5.3.el6_4.1.x86_64
> nspr-4.9.2-1.el6.x86_64 nss-3.14.0.0-12.el6.x86_64
> nss-softokn-freebl-3.12.9-11.el6.x86_64 nss-util-3.14.0.0-2.el6.x86_64
> openldap-2.4.23-32.el6_4.1.x86_64 openssl-1.0.0-27.el6_4.2.x86_64
> postgresql92-libs-9.2.4-1PGDG.rhel6.x86_64 zlib-1.2.3-29.el6.x86_64
> (gdb) where
> #0  0x000000000055e602 in free_to_params (tb=0x7f31fee421a0)
>      at parser/parse_to.c:827
> #1  0x000000000055e658 in free_to (tb=0x7f31fee421a0) at
> parser/parse_to.c:838
> #2  0x000000000053e2a9 in clean_hdr_field (hf=0x7f31fee23bc0)
>      at parser/hf.c:113
> #3  0x000000000053e51d in free_hdr_field_lst (hf=0x7f31fee20a60)
>      at parser/hf.c:223
> #4  0x0000000000542d04 in free_sip_msg (msg=0x7f31fee40df0)
>      at parser/msg_parser.c:729
> #5  0x000000000049e39d in receive_msg (
>      buf=0x9065c0 "SIP/2.0 480 Temporarily Unavailable\r\nVia:
> SIP/2.0/UDP 55.177.31.199;branch=z9hG4bKbe3a.dab6345.0\r\nVia:
> SIP/2.0/UDP
> 192.13.219.87:5060;branch=z9hG4bK-1a97-521d9f57-331967d3-3174bfdc\r\nRecord-Route:
> <sip"..., len=866,
>      rcv_info=0x7fff34138bd0) at receive.c:296
> #6  0x000000000052ffa1 in udp_rcv_loop () at udp_server.c:557
> #7  0x0000000000467de2 in main_loop () at main.c:1638
> #8  0x000000000046ad8b in main (argc=13, argv=0x7fff34138f08) at
> main.c:2566
>
> -- Alex
>
> On 08/27/2013 08:49 AM, Alex Balashov wrote:
>
>> Hi Daniel,
>
>>
>> On 08/27/2013 08:47 AM, Daniel-Constantin Mierla wrote:
>>
>>> Hello,
>>>
>>> can you try this patch?
>>> -
>>> http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=14835f89fc2b761f73a0caad67d229ec3fedba29
>>>
>>>
>>>
>>>
>>> One reason for such crash could be double-free, which could eventually
>>> happen because the pointer to params was not reset after freeing the
>>> list.
>>
>> I will certainly try it, thank you.
>>
>> However, it is curious that this crash occurs only in this exact
>> situation, only when calling this PBX, only when it has two registrants
>> to fork among, only when I use this combination of request
>> routes/subroutines.
>>
>
>


-- 
Alex Balashov - Principal
Evariste Systems LLC
235 E Ponce de Leon Ave
Suite 106
Decatur, GA 30030
United States
Tel: +1-678-954-0670
Web: http://www.evaristesys.com/, http://www.alexbalashov.com/

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