sergey-safarov created an issue (kamailio/kamailio#4356)

### Description

Kamailio core generated when `siptrace` module tries to relay a message generated by `uac` module.

### Troubleshooting

#### Reproduction To reproduce the issue need to start Kamailio with the config file. ``` #!KAMAILIO

#!define L_INFO 2 #!trydef TROUBLESHOOT_NET "" local.trace_troubleshooting_net = TROUBLESHOOT_NET descr "trace all SIP messages from given network"

# IPv4 listeners listen=udp:lan

debug=L_INFO log_stderror=yes

loadmodule "pv.so" loadmodule "tm.so"

####### DATABASE module ########## #!substdef "!KAMAILIO_DB_URL!mysql://kamailio:change_me@127.0.0.1:3306/kamailio!g" loadmodule "db_mysql.so"

loadmodule "uac.so" modparam("uac", "reg_db_url", "KAMAILIO_DB_URL") modparam("uac", "reg_contact_addr", "192.168.1.2:5080") modparam("uac","restore_mode","none")

####### siptrace module ########## loadmodule "siptrace.so" modparam("siptrace", "duplicate_uri", "sip:127.0.0.1:9060") modparam("siptrace", "trace_to_database", 0) modparam("siptrace", "trace_on", 1) modparam("siptrace", "trace_mode", 1)

####### Routing Logic ######## request_route { drop; }

event_route[siptrace:msg] { if ($sel(cfg_get.local.trace_troubleshooting_net) != "") { return; } } ``` In the database, need to inserta record ```sql INSERT INTO `uacreg` VALUES (1,'120','120','example.com','120','10.191.1.21','','120','','8e789f9318c98b9ffd4f0fd9e0b8a747','sip:10.191.1.21;transport=udp',120,0,0,'','');

```

#### Debugging Data

Backtrace for the generated core in the attached file [kamailio-bt-full.txt](https://github.com/user-attachments/files/21671121/kamailio-bt-full.txt)

#### Log Messages ``` / # kamailio -DD --atexit=no -m 64 -M 8 -E 0(43) INFO: <core> [core/sctp_core.c:74]: sctp_core_check_support(): SCTP API not enabled - if you want to use it, load sctp module Listening on udp: 10.191.1.20:5060 Aliases: udp: ip-10-191-1-20.ec2.internal:5060

0(43) INFO: <core> [core/tcp_main.c:5232]: init_tcp(): using epoll_lt as the io watch method (auto detected) 0(43) INFO: siptrace [siptrace.c:438]: mod_init(): can't load dlg api. Will not install dialog callbacks. 0(43) ERROR: siptrace [../../modules/sl/sl.h:107]: sl_load_api(): cannot find bind_sl 0(43) WARNING: siptrace [siptrace.c:450]: mod_init(): cannot bind to SL API. Will not install sl callbacks. 0(43) INFO: <core> [main.c:3233]: main(): processes (at least): 14 - shm size: 67108864 - pkg size: 8388608 0(43) INFO: <core> [core/udp_server.c:163]: probe_max_receive_buffer(): SO_RCVBUF is initially 212992 for fd 4 0(43) INFO: <core> [core/udp_server.c:233]: probe_max_receive_buffer(): SO_RCVBUF is finally 425984 on fd 4 0(43) INFO: <core> [core/udp_server.c:264]: probe_max_send_buffer(): SO_SNDBUF is initially 212992 for fd 4 0(43) INFO: <core> [core/udp_server.c:334]: probe_max_send_buffer(): SO_SNDBUF is finally 425984 on fd 4 0(43) ALERT: <core> [main.c:805]: handle_sigs(): child process 55 exited by a signal 11 0(43) ALERT: <core> [main.c:809]: handle_sigs(): core was generated 0(43) INFO: <core> [main.c:832]: handle_sigs(): terminating due to SIGCHLD 1(44) INFO: <core> [main.c:888]: sig_usr(): signal 15 received 2(45) INFO: <core> [main.c:888]: sig_usr(): signal 15 received 3(46) INFO: <core> [main.c:888]: sig_usr(): signal 15 received 4(47) INFO: <core> [main.c:888]: sig_usr(): signal 15 received 5(48) INFO: <core> [main.c:888]: sig_usr(): signal 15 received 6(49) INFO: <core> [main.c:888]: sig_usr(): signal 15 received 7(50) INFO: <core> [main.c:888]: sig_usr(): signal 15 received 8(51) INFO: <core> [main.c:888]: sig_usr(): signal 15 received 9(52) INFO: <core> [main.c:888]: sig_usr(): signal 15 received 13(56) INFO: <core> [main.c:888]: sig_usr(): signal 15 received 10(53) INFO: <core> [main.c:888]: sig_usr(): signal 15 received 11(54) INFO: <core> [main.c:888]: sig_usr(): signal 15 received 0(43) INFO: <core> [core/sctp_core.c:53]: sctp_core_destroy(): SCTP API not initialized ``` ### Possible Solutions As temporary workaround we use ```diff diff --git a/src/core/cfg/cfg_select.c b/src/core/cfg/cfg_select.c index f948dd4ab4..1a36ef378a 100644 --- a/src/core/cfg/cfg_select.c +++ b/src/core/cfg/cfg_select.c @@ -207,8 +207,10 @@ int select_cfg_var(str *res, select_t *s, struct sip_msg *msg) group = (cfg_group_t *)s->params[1].v.p; var = (cfg_mapping_t *)s->params[2].v.p;

- if(!group || !var) + if(!group || !var || NULL == *(group->handle)) { + LM_ERR("incorrect input args\n"); return -1; + }

/* use the module's handle to access the variable, so the variables * are read from the local config */ ```

### Additional Information

* **Kamailio Version** - output of `kamailio -v`

``` / # kamailio -v version: kamailio 5.8.4 (x86_64/linux) flags: USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MMAP, PKG_MALLOC, MEM_JOIN_FREE, Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLOCKLIST, HAVE_RESOLV_RES, TLS_PTHREAD_MUTEX_SHARED ADAPTIVE_WAIT_LOOPS 1024, MAX_RECV_BUFFER_SIZE 262144, MAX_SEND_BUFFER_SIZE 262144, MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. id: unknown compiled on 14:31:12 Nov 18 2024 with gcc 14.2.0 ```

* **Operating System**:

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``` NAME="Alpine Linux" ID=alpine VERSION_ID=3.21.4 PRETTY_NAME="Alpine Linux v3.21" HOME_URL="https://alpinelinux.org/" BUG_REPORT_URL="https://gitlab.alpinelinux.org/alpine/aports/-/issues" ``` uname ``` Linux sbc0-site0-stage.ph.nga911.com 6.15.5-200.fc42.x86_64 #1 SMP PREEMPT_DYNAMIC Sun Jul 6 09:16:17 UTC 2025 x86_64 Linux ```