Fix memory leak when UnsubscribePacket is reused (#617)

awslabs · May 1, 2024 · e092720 · e092720
1 parent 414d8c5
commit e092720
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Showing 3 changed files with 30 additions and 1 deletion.
diff --git a/source/mqtt/Mqtt5Packets.cpp b/source/mqtt/Mqtt5Packets.cpp
@@ -138,7 +138,7 @@ namespace Aws
                 const Crt::Vector<String> &stringVector,
                 Allocator *allocator)
             {
-                AWS_ZERO_STRUCT(dst);
+                aws_array_list_clean_up(&dst);
 
                 if (aws_array_list_init_dynamic(&dst, allocator, stringVector.size(), sizeof(aws_byte_cursor)) !=
                     AWS_OP_SUCCESS)

diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
@@ -235,6 +235,7 @@ if(NOT BYO_CRYPTO)
     add_net_test_case(Mqtt5NullPublish)
     add_net_test_case(Mqtt5NullSubscribe)
     add_net_test_case(Mqtt5NullUnsubscribe)
+    add_net_test_case(Mqtt5ReuseUnsubscribePacket)
     add_net_test_case(Mqtt5QoS1SubPub)
     add_net_test_case(Mqtt5RetainSetAndClear)
 

diff --git a/tests/Mqtt5ClientTest.cpp b/tests/Mqtt5ClientTest.cpp
@@ -2285,6 +2285,34 @@ static int s_TestMqtt5NullUnsubscribe(Aws::Crt::Allocator *allocator, void *)
 }
 AWS_TEST_CASE(Mqtt5NullUnsubscribe, s_TestMqtt5NullUnsubscribe)
 
+/*
+ * Reuse unsubscribe packet test.
+ * The scenario in this test once caused memory leak, so the test ensures the issue is fixed for good.
+ */
+static int s_TestMqtt5ReuseUnsubscribePacket(Aws::Crt::Allocator *allocator, void *)
+{
+    ApiHandle apiHandle(allocator);
+
+    const String TEST_TOPIC = "test/s_TestMqtt5NullUnsubscribe" + Aws::Crt::UUID().ToString();
+
+    Mqtt5::Mqtt5ClientOptions mqtt5Options(allocator);
+    mqtt5Options.WithHostName("www.example.com").WithPort(1111);
+    std::shared_ptr<Mqtt5::Mqtt5Client> mqtt5Client = Mqtt5::Mqtt5Client::NewMqtt5Client(mqtt5Options, allocator);
+    ASSERT_TRUE(mqtt5Client);
+
+    Vector<String> unsubList{TEST_TOPIC};
+    std::shared_ptr<Mqtt5::UnsubscribePacket> unsubscribe = std::make_shared<Mqtt5::UnsubscribePacket>(allocator);
+    unsubscribe->WithTopicFilters(unsubList);
+    ASSERT_TRUE(mqtt5Client->Unsubscribe(unsubscribe));
+    /* Unsubscribe once again using the same UnsubscribePacket. */
+    ASSERT_TRUE(mqtt5Client->Unsubscribe(unsubscribe));
+
+    ASSERT_TRUE(mqtt5Client->Stop());
+
+    return AWS_OP_SUCCESS;
+}
+AWS_TEST_CASE(Mqtt5ReuseUnsubscribePacket, s_TestMqtt5ReuseUnsubscribePacket)
+
 //////////////////////////////////////////////////////////
 // QoS1 Test Cases [QoS1-UC]
 //////////////////////////////////////////////////////////