ASAN reports memleaks for tests/bug330.phpt

[mikhainin]

Description

The following code:

<?php
$conf = new Conf();
$conf->set('group.id','test');
$consumer = new KafkaConsumer($conf);
$topic = $consumer->newTopic('test');
unset($topic);
var_dump(isset($topic));

When built with ASAN and run like this:

ZEND_DONT_UNLOAD_MODULES=1 ./tests/bug330.sh

Resulted in this output:

    #0 0x7fc596191db0 in strdup (/lib64/libasan.so.5+0x3bdb0)
    #1 0x7fc59080c4ee in rd_strdup /home/mgalanin/php-build/librdkafka-2.0.2/src/rd.h:156
    #2 0x7fc59080fe06 in rd_kafka_anyconf_set_prop0 /home/mgalanin/php-build/librdkafka-2.0.2/src/rdkafka_conf.c:1725
    #3 0x7fc59081237f in rd_kafka_defaultconf_set /home/mgalanin/php-build/librdkafka-2.0.2/src/rdkafka_conf.c:2171
    #4 0x7fc59081248e in rd_kafka_topic_conf_new /home/mgalanin/php-build/librdkafka-2.0.2/src/rdkafka_conf.c:2191
    #5 0x7fc590802a93 in rd_kafka_topic_new0 /home/mgalanin/php-build/librdkafka-2.0.2/src/rdkafka_topic.c:303
    #6 0x7fc590804450 in rd_kafka_topic_new /home/mgalanin/php-build/librdkafka-2.0.2/src/rdkafka_topic.c:510
    #7 0x7fc590ff2da7 in zim_RdKafka_KafkaConsumer_newTopic /home/mgalanin/php-build/github.com-tony2001-php-rdkafka/kafka_consumer.c:561
    #8 0xd3438d in ZEND_DO_FCALL_SPEC_RETVAL_USED_HANDLER /home/mgalanin/php-build/php-sources/Zend/zend_vm_execute.h:1863
    #9 0xe7687e in execute_ex /home/mgalanin/php-build/php-sources/Zend/zend_vm_execute.h:55195
    #10 0xe83e40 in zend_execute /home/mgalanin/php-build/php-sources/Zend/zend_vm_execute.h:59523
    #11 0xca0a4d in zend_execute_scripts /home/mgalanin/php-build/php-sources/Zend/zend.c:1826
    #12 0xb309dc in php_execute_script /home/mgalanin/php-build/php-sources/main/main.c:2568
    #13 0xf1b6ff in do_cli /home/mgalanin/php-build/php-sources/sapi/cli/php_cli.c:949
    #14 0xf1d9dc in main /home/mgalanin/php-build/php-sources/sapi/cli/php_cli.c:1341
    #15 0x7fc594c90d84 in __libc_start_main (/lib64/libc.so.6+0x3ad84)

From what I can see, PHP_METHOD(RdKafka_KafkaConsumer, newTopic) calls rd_kafka_topic_new() but the result is never gets freed as kafka_topic_free() only considers that it can be referred from a kafka_object

I was able to fix the problem like this:

diff --git a/topic.c b/topic.c
index f1c0f7f..08b20d2 100644
--- a/topic.c
+++ b/topic.c
@@ -57,6 +57,9 @@ static void kafka_topic_free(zend_object *object) /* {{{ */
         if (kafka_intern) {
             zend_hash_index_del(&kafka_intern->topics, (zend_ulong)intern);
         }
+    } else if (intern->rkt) {
+        // the class created via KafkaConsumer::newTopic()
+        rd_kafka_topic_destroy(intern->rkt);
     }
 
     zend_object_std_dtor(&intern->std);

but not sure if it's the right way

php-rdkafka Version

6.0.3 (latest revision from "6.x" branch)

librdkafka Version

2.0.2

PHP Version

8.0.28

Operating System

No response

Kafka Version

No response