Hi,

i've just ran cppcheck (http://cppcheck.sourceforge.net/, a static code analyser) on zabbix codebase (svn revision 40328) and it found:

[src/libs/zbxregexp/gnuregex.c:1176]: (error) Memory leak: compile_stack.stack
[src/libs/zbxregexp/gnuregex.c:4849]: (error) Memory leak: regs.start
[src/libs/zbxregexp/gnuregex.c:4849]: (error) Memory leak: regs.end
[src/libs/zbxregexp/gnuregex.c:2603]: (error) Memory leak: fail_stack.stack

FYI once cppcheck found a memory leak it stop checking for this variable,
so you have to rerun it after correcting (you have to 'free' before each return)

to run cppcheck:

cppcheck --force -j8 . 2> ../cppcheck-zabbix.txt

You can also run it with

cppcheck --force --enable=all -j7 . 2> ../cppcheck-zabbix2.txt

you will have many more advice but also more false positive

You should consider running cppcheck before each release