### Description

<!-- Explain what you did, what you expected to happen, and what actually happened. --> We are buidling some kind of our own rtpengine dispatcher based on our own algorithm using kemi Lua.

In one of the functions we are calling:

`local reqBody = function(command, params)

return json.encode({ jsonrpc = "2.0", method = "rtpengine." .. command, params = params })

end

KSR.jsonrpcs.exec(reqBody("show", { "all" })) local data = json.decode(KSR.pv.get("$jsonrpl(body)")) ` And watching **free_mem** decrasing in case of every call of this function

If we are commenting this - nothing happens

P.S. We are doing the same for the dispatcher module but did not find memory leak for it:

`local reqBody = function (command,params)

return json.encode( { jsonrpc = "2.0", method = "dispatcher." ..command, params = params } )

end

KSR.jsonrpcs.exec(reqBody( "list" ) ) local data = json.decode( KSR.pv.get("$jsonrpl(body)") ) ` ### Troubleshooting

#### Reproduction

To reproduce this issue suppose will be enough to call code above #### Debugging Data

test results for 10000 calls total/300 per second (sipp based)

memory stats on the start

shmem:fragments = 2 |   shmem:free_size = 63131408 shmem:max_used_size = 3994704 shmem:real_used_size = 3977456 shmem:total_size = 67108864 shmem:used_size = 3205144

memory stats on the end

shmem:fragments = 5 |   shmem:free_size = 60106232 shmem:max_used_size = 7019952 shmem:real_used_size = 7002632 shmem:total_size = 67108864 shmem:used_size = 4150008

### Additional Information

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

``` version: kamailio 5.1.6 (x86_64/linux) 7d1964 flags: STATS: Off, USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MEM, SHM_MMAP, PKG_MALLOC, 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_BLACKLIST, HAVE_RESOLV_RES ADAPTIVE_WAIT_LOOPS=1024, MAX_RECV_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: 7d1964 compiled on 03:23:23 Oct 5 2018 with gcc 6.3.0 ```

* **Operating System**:

<!-- Details about the operating system, the type: Linux (e.g.,: Debian 8.4, Ubuntu 16.04, CentOS 7.1, ...), MacOS, xBSD, Solaris, ...; Kernel details (output of `uname -a`) -->

``` 1 machine: SMP Debian 4.9.110-3+deb9u6 (2018-10-08) x86_64 GNU/Linux 2 machine: SMP Debian 4.9.110-3+deb9u2 (2018-08-13) x86_64 GNU/Linux ``` If will need any additional info just let me know P.S. We also tried to find what can give this behavior on the rtpengine.c but didn't figured out yet