Question about ldap_search_ext_s and memory leak

[Jean-Marc Choulet <jm130794@gmail.com>]

Hello,

I have a little with this very simple program :

#include <iostream>
#include <stdlib.h>
#define LDAP_DEPRECATED 1
#include <ldap.h>

using namespace std;

const char* server = "ldap://ldap.xxxx.fr";;
const char* cacert_file = "cacert.pem";
const char* root_dn = "cn=replicator,ou=DSA,dc=xxxx,dc=fr";
const char* root_pw = "xxxx";
const char* aliased_people_dn ="ou=AliasedPeople,dc=xxxx,dc=fr";

int main(int argc, char *argv[])
{
    if (argc != 3) {
        cerr << "Usage: " << argv[0] << " username password" << endl;
        return 1;
    }

    LDAP *ld;
    int version = LDAP_VERSION3;
    int rc;

    if ((rc = ldap_initialize(&ld, server)) != LDAP_SUCCESS) {
        cerr << "ldap_initialize: " << server << endl;
        return EXIT_FAILURE;
    }

    if ((rc = ldap_set_option(ld, LDAP_OPT_PROTOCOL_VERSION, &version)) 
!= LDAP_OPT_SUCCESS) {
        cerr << "ldap_set_option error: " << ldap_err2string(rc) << endl;
        return EXIT_FAILURE;
    }

    if ((rc = ldap_set_option(NULL, LDAP_OPT_X_TLS_CACERTFILE, 
cacert_file)) != LDAP_OPT_SUCCESS )
    {
        cerr << "ldap_set_option error: " << ldap_err2string(rc) << endl;
        return EXIT_FAILURE;
    }

    if ((rc = ldap_start_tls_s(ld, NULL, NULL)) != LDAP_SUCCESS)
    {
        cerr << "ldap_start_tls_s error: " << ldap_err2string(rc) << endl;
        return EXIT_FAILURE;
    }

    if ((rc = ldap_bind_s(ld, root_dn, root_pw, LDAP_AUTH_SIMPLE)) != 
LDAP_SUCCESS) {
        cerr << "ldap_bind_s: " << ldap_err2string(rc) << endl;
        return EXIT_FAILURE;
    }

    cout << "user replicator authenticated :)." << endl;

    LDAPMessage *pResult;
    struct berval cred;
    char *pDN;

    std::string filter("uid=" + string(argv[1]));

    rc = ldap_search_ext_s(ld, aliased_people_dn, LDAP_SCOPE_SUBTREE,
                           filter.c_str(), NULL, 0, NULL, NULL,
                           NULL, LDAP_NO_LIMIT, &pResult);

    if (rc != LDAP_SUCCESS)
    {
        cerr << "ldap_search_ext_s error: " << ldap_err2string(rc) << endl;
        ldap_unbind_s(ld);
        return EXIT_FAILURE;
    }

    struct berval **vals;
    LDAPMessage    *pEntry;
    string          user_dn;

    if (ldap_count_entries(ld, pResult) == 1) {
        pEntry = ldap_first_entry(ld, pResult);
        pDN = ldap_get_dn(ld, pEntry);
        vals = ldap_get_values_len(ld, pEntry, "aliasedObjectName");

        if (vals) {
            user_dn = vals[0]->bv_val;
            ldap_value_free_len(vals);
        }
        ldap_memfree(pDN);
    }
    else {
        cout << "aliasedObjectName attribute not found" << endl;
        ldap_unbind_s(ld);
        return EXIT_FAILURE;
    }

    ldap_memfree(pResult);

    if ((rc = ldap_bind_s(ld, user_dn.c_str(), argv[2], 
LDAP_AUTH_SIMPLE)) != LDAP_SUCCESS) {
        cerr << "user " << argv[1] << " not authenticated" << endl;
        ldap_unbind_s(ld);
        return EXIT_FAILURE;
    }

    cout << "user " << argv[1] << " (" << user_dn << ") authenticated" 
<< endl;

    ldap_unbind_s(ld);

    return EXIT_SUCCESS;
}

My program works fine but, if I use valgrind, I have memory leaks :

valgrind --leak-check=full ./ldapauth.exe toto secret
==13616== Memcheck, a memory error detector
==13616== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==13616== Using Valgrind-3.10.0.SVN and LibVEX; rerun with -h for 
copyright info
==13616== Command: ./ldapauth.exe toto secret
==13616==
user replicator authenticated :).
user toto (uid=toto,ou=People,ou=17,dc=xxxx,dc=fr) authenticated
==13616== Warning: invalid file descriptor -1 in syscall write()
==13616==
==13616== HEAP SUMMARY:
==13616==     in use at exit: 260,453 bytes in 1,157 blocks
==13616==   total heap usage: 13,835 allocs, 12,678 frees, 2,138,249 
bytes allocated
==13616==
==13616== 149 (56 direct, 93 indirect) bytes in 1 blocks are definitely 
lost in loss record 65 of 84
==13616==    at 0x4C2CC70: calloc (in 
/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==13616==    by 0x596E604: ber_memcalloc_x (in 
/usr/lib/x86_64-linux-gnu/liblber-2.4.so.2.8.3)
==13616==    by 0x4E48687: ldap_result (in 
/usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2.8.3)
==13616==    by 0x4E4ACA6: ldap_pvt_search_s (in 
/usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2.8.3)
==13616==    by 0x4E4AD4F: ldap_search_ext_s (in 
/usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2.8.3)
==13616==    by 0x4016D4: main (ldapauth.cpp:72)
==13616==
==13616== 271 (80 direct, 191 indirect) bytes in 1 blocks are definitely 
lost in loss record 69 of 84
==13616==    at 0x4C2CC70: calloc (in 
/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==13616==    by 0x596E604: ber_memcalloc_x (in 
/usr/lib/x86_64-linux-gnu/liblber-2.4.so.2.8.3)
==13616==    by 0x596D031: ber_alloc_t (in 
/usr/lib/x86_64-linux-gnu/liblber-2.4.so.2.8.3)
==13616==    by 0x4E5AA22: ldap_alloc_ber_with_options (in 
/usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2.8.3)
==13616==    by 0x4E48BB7: ldap_result (in 
/usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2.8.3)
==13616==    by 0x4E4ACA6: ldap_pvt_search_s (in 
/usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2.8.3)
==13616==    by 0x4E4AD4F: ldap_search_ext_s (in 
/usr/lib/x86_64-linux-gnu/libldap_r-2.4.so.2.8.3)
==13616==    by 0x4016D4: main (ldapauth.cpp:72)
==13616==
==13616== LEAK SUMMARY:
==13616==    definitely lost: 136 bytes in 2 blocks
==13616==    indirectly lost: 284 bytes in 3 blocks
==13616==      possibly lost: 0 bytes in 0 blocks
==13616==    still reachable: 260,033 bytes in 1,152 blocks
==13616==         suppressed: 0 bytes in 0 blocks
==13616== Reachable blocks (those to which a pointer was found) are not 
shown.
==13616== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==13616==
==13616== For counts of detected and suppressed errors, rerun with: -v
==13616== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 0 from 0)

I don't understand why. Do you have a idea ?

I work on Ubuntu 14.04. The OpenLDAP version is  2.4.31.

Thanks,

Jean-Marc.