T102pdu_build_clib.c: Fix memory leaks

[moshekaplan]

T102pdu_build_clib.c: Fix memory leaks

[moshekaplan]

Before:

~/Desktop/net-snmp/testing$ ASAN_OPTIONS="detect_leaks=1:log_path=$PWD/asan.log:log_exe_name=1: print_cmdline=1"  ./RUNFULLTESTS -g "unit-tests" -r 102
PDU building .. No subtests run 

Test Summary Report
-------------------
PDU building (Wstat: 0 Tests: 0 Failed: 0)
  Parse errors: No plan found in TAP output
Files=1, Tests=0,  0 wallclock secs ( 0.02 usr  0.00 sys +  0.15 cusr  0.04 csys =  0.21 CPU)
Result: FAIL

~/Desktop/net-snmp/testing$ cat asan.log.B102pdu_build_clib.273886 

=================================================================
==B102pdu_build_clib==273886==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 280 byte(s) in 1 object(s) allocated from:
    #0 0x7f7b10cde9a7 in __interceptor_calloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:77
    #1 0x7f7b0f099787 in snmp_pdu_create /home/user/Desktop/net-snmp/snmplib/snmp_client.c:134
    #2 0x55a11703377d in main /home/user/Desktop/net-snmp/testing/fulltests/unit-tests/T102pdu_build_clib.c:32
    #3 0x7f7b0e623a8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

Indirect leak of 5 byte(s) in 1 object(s) allocated from:
    #0 0x7f7b10cdefef in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:69
    #1 0x7f7b0f1b7b06 in netsnmp_memdup /home/user/Desktop/net-snmp/snmplib/tools.c:285
    #2 0x7f7b0f131bdd in _snmp_build /home/user/Desktop/net-snmp/snmplib/snmp_api.c:3099
    #3 0x7f7b0f1339e0 in snmp_build /home/user/Desktop/net-snmp/snmplib/snmp_api.c:3290
    #4 0x55a11703389d in main /home/user/Desktop/net-snmp/testing/fulltests/unit-tests/T102pdu_build_clib.c:37
    #5 0x7f7b0e623a8f in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

After:

~/Desktop/net-snmp/testing$ ASAN_OPTIONS="detect_leaks=1:log_path=$PWD/asan.log:log_exe_name=1: print_cmdline=1"  ./RUNFULLTESTS -g "unit-tests" -r 102
PDU building .. ok   
All tests successful.
Files=1, Tests=5,  0 wallclock secs ( 0.01 usr  0.01 sys +  0.06 cusr  0.03 csys =  0.11 CPU)
Result: PASS

[moshekaplan]

Note: It may make sense to change the later snmp_pdu_create commands to use SNMP_MSG_SET and SNMP_MSG_INFORM, instead of creating the PDU and then modifying the command field afterward. I only did not because I did not want to change more of the test than minimally needed to make it not trigger LeakSanitizer.

[bvanassche]

Thanks for the patch!