https://bugs.openldap.org/show_bug.cgi?id=9696
Issue ID: 9696 Summary: OpenSSL implementation of LDAP_OPT_X_TLS_PEERCERT leaks memory Product: OpenLDAP Version: 2.4.57 Hardware: All OS: All Status: UNCONFIRMED Keywords: needs_review Severity: normal Priority: --- Component: libraries Assignee: bugs@openldap.org Reporter: cheimes@redhat.com Target Milestone: ---
The OpenSSL implementation of ldap_get_option() LDAP_OPT_X_TLS_PEERCERT leaks memory. The internal function tlso_session_peercert() uses SSL_get_peer_certificate() to access the server certificate. SSL_get_peer_certificate() increases the reference counter of the peer cert by one. The code is missing a X509_free() call to decref the internal reference counter by one.
I also recommend that you check the return value of SSL_get_peer_certificate() for NULL. There are cases when a TLS session does not have access to a peer certificate, e.g. session resumption.
Valgrind log:
==586962== 16,044 (1,056 direct, 14,988 indirect) bytes in 3 blocks are definitely lost in loss record 6,355 of 6,374 ==586962== at 0x484086F: malloc (vg_replace_malloc.c:380) ==586962== by 0x16981A4D: CRYPTO_zalloc (mem.c:230) ==586962== by 0x168CC823: asn1_item_embed_new (tasn_new.c:122) ==586962== by 0x168CE12A: asn1_item_embed_d2i (tasn_dec.c:325) ==586962== by 0x168CE341: ASN1_item_ex_d2i (tasn_dec.c:124) ==586962== by 0x168CE3CE: ASN1_item_d2i (tasn_dec.c:114) ==586962== by 0x1744B7CC: tls_process_server_certificate (statem_clnt.c:1853)