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#### Description I faced an issue with memory leak in case drop NOTIFY messages in the "local-request" event route in `mem_copy_subs` and `build_uac_req`

analysis of mem leak: kamcmd corex.shm_summary <code>... Mar 23 12:00:28 pbx kamailio[72308]: NOTICE: fm_status: fm_sums(): count= 11 size= 7520 bytes from presence: hash.c: mem_copy_subs(141)<br> Mar 23 12:00:28 pbx kamailio[72308]: NOTICE: fm_status: fm_sums(): count= 23 size= 22536 bytes from tm: t_msgbuilder.c: build_uac_req(1618) ...</code>

a lot of dropped messages in local-request event route

<code>... Mar 23 12:01:09 pbx kamailio[72308]: NOTICE: fm_status: fm_sums(): count= 83 size= 51256 bytes from presence: hash.c: mem_copy_subs(141) Mar 23 12:01:09 pbx kamailio[72308]: NOTICE: fm_status: fm_sums(): count= 98 size= 116864 bytes from tm: t_msgbuilder.c: build_uac_req(1618) ...</code>

no messages, no activities

<code>... Mar 23 12:02:34 pbx kamailio[72308]: NOTICE: fm_status: fm_sums(): count= 83 size= 51256 bytes from presence: hash.c: mem_copy_subs(141) Mar 23 12:02:34 pbx kamailio[72308]: NOTICE: fm_status: fm_sums(): count= 96 size= 115432 bytes from tm: t_msgbuilder.c: build_uac_req(1618) ...</code>

In the code, we have a comment like "never free cbp here because if t_uac_prepare fails, cbp is not freed and thus caller has no chance to discover if it is freed or not", but we'll free the cbp in two cases: 1. in case of error, but we have if (ret == E_DROP) then ret = 0; (so, no error result) 2. in case call insert_tmcb for cbp, but we don't do it for E_DROP You can view, comment on, or merge this pull request online at:

https://github.com/kamailio/kamailio/pull/3403

-- Commit Summary --

* tm: memory leak in case dropping messages in local-request event route

-- File Changes --

M src/modules/tm/uac.c (8)

-- Patch Links --

https://github.com/kamailio/kamailio/pull/3403.patch https://github.com/kamailio/kamailio/pull/3403.diff