tests: internal: upstream_tls: verify TLS session destroy prevents double-free

Signed-off-by: Shelby Hagman <shelbyzh@amazon.com>

Author: ShelbyZ

tests/internal/upstream_tls.c

@@ -18,6 +18,7 @@
 
 struct test_backend_ctx {
     int invalidate_calls;
+    int destroy_calls;
 };
 
 static void test_session_invalidate(void *session)
@@ -29,6 +30,46 @@ static void test_session_invalidate(void *session)
     }
 }
 
+static int test_session_destroy(void *session)
+{
+    struct test_backend_ctx *ctx = session;
+
+    if (ctx != NULL) {
+        ctx->destroy_calls++;
+    }
+
+    return 0;
+}
+
+static int setup_conn(struct flb_connection *conn,
+                      struct flb_upstream *upstream,
+                      struct flb_config *config,
+                      flb_pipefd_t *socket_pair)
+{
+    if (flb_pipe_create(socket_pair) != 0) {
+        return -1;
+    }
+
+    config->is_shutting_down    = FLB_FALSE;
+    upstream->base.config       = config;
+    upstream->base.net.keepalive = FLB_FALSE;
+    upstream->tcp_host          = "example";
+    upstream->tcp_port          = 443;
+    flb_upstream_queue_init(&upstream->queue);
+
+    conn->fd          = socket_pair[0];
+    conn->event.fd    = conn->fd;
+    conn->event.status = 0;
+    conn->stream      = (struct flb_stream *) upstream;
+    conn->net         = &upstream->base.net;
+    conn->net_error   = 0;
+
+    mk_list_init(&conn->_head);
+    mk_list_add(&conn->_head, &upstream->queue.busy_queue);
+
+    return 0;
+}
+
 void test_prepare_destroy_conn_marks_tls_session_stale(void)
 {
     struct test_backend_ctx backend_session = {0};
@@ -38,53 +79,28 @@ void test_prepare_destroy_conn_marks_tls_session_stale(void)
     struct flb_connection conn = {0};
     struct flb_upstream upstream = {0};
     struct flb_config config = {0};
-    struct flb_upstream_queue *queue;
     flb_pipefd_t socket_pair[2];
-    int ret;
 
 #ifdef FLB_SYSTEM_WINDOWS
     WSADATA wsa_data;
-
     WSAStartup(0x0201, &wsa_data);
 #endif
 
-    ret = flb_pipe_create(socket_pair);
-    TEST_CHECK(ret == 0);
+    TEST_CHECK(setup_conn(&conn, &upstream, &config, socket_pair) == 0);
 
     backend_api.session_invalidate = test_session_invalidate;
     tls_context.api = &backend_api;
-
     tls_session.ptr = &backend_session;
     tls_session.tls = &tls_context;
     tls_session.connection = &conn;
-
-    config.is_shutting_down = FLB_FALSE;
-    upstream.base.config = &config;
-    upstream.base.net.keepalive = FLB_FALSE;
-    upstream.tcp_host = "example";
-    upstream.tcp_port = 443;
-
-    flb_upstream_queue_init(&upstream.queue);
-
-    conn.fd = socket_pair[0];
-    conn.event.fd = conn.fd;
-    conn.event.status = 0;
-    conn.stream = (struct flb_stream *) &upstream;
-    conn.net = &upstream.base.net;
     conn.tls_session = &tls_session;
-    conn.net_error = 0;
-
-    mk_list_init(&conn._head);
-    queue = &upstream.queue;
-    mk_list_add(&conn._head, &queue->busy_queue);
 
-    ret = flb_upstream_conn_release(&conn);
-    TEST_CHECK(ret == 0);
+    TEST_CHECK(flb_upstream_conn_release(&conn) == 0);
 
     TEST_CHECK(backend_session.invalidate_calls == 1);
     TEST_CHECK(conn.fd == -1);
     TEST_CHECK(conn.event.fd == -1);
-    TEST_CHECK(mk_list_size(&queue->destroy_queue) == 1);
+    TEST_CHECK(mk_list_size(&upstream.queue.destroy_queue) == 1);
     TEST_CHECK(conn.shutdown_flag == FLB_TRUE);
 
     flb_pipe_close(socket_pair[1]);
@@ -94,11 +110,63 @@ void test_prepare_destroy_conn_marks_tls_session_stale(void)
 #endif
 }
 
+void test_tls_session_destroy_no_double_free(void)
+{
+    struct test_backend_ctx backend_session = {0};
+    struct flb_tls_backend backend_api = {0};
+    struct flb_tls tls_context = {0};
+    struct flb_tls_session *tls_session;
+    struct flb_connection *conn;
+    struct flb_upstream upstream = {0};
+    struct flb_config config = {0};
+    flb_pipefd_t socket_pair[2];
+
+#ifdef FLB_SYSTEM_WINDOWS
+    WSADATA wsa_data;
+    WSAStartup(0x0201, &wsa_data);
+#endif
+
+    /* heap-allocate conn to match production; pending_destroy calls flb_free on it */
+    conn = flb_calloc(1, sizeof(struct flb_connection));
+    TEST_CHECK(conn != NULL);
+    conn->dynamically_allocated = FLB_TRUE;
+    TEST_CHECK(setup_conn(conn, &upstream, &config, socket_pair) == 0);
+
+    backend_api.session_invalidate = test_session_invalidate;
+    backend_api.session_destroy    = test_session_destroy;
+    tls_context.api = &backend_api;
+
+    /* heap-allocated to match production; flb_tls_session_destroy calls flb_free */
+    tls_session = flb_calloc(1, sizeof(struct flb_tls_session));
+    TEST_CHECK(tls_session != NULL);
+    tls_session->ptr        = &backend_session;
+    tls_session->tls        = &tls_context;
+    tls_session->connection = conn;
+    conn->tls_session       = tls_session;
+
+    /* explicit destroy before release — the fix */
+    TEST_CHECK(flb_tls_session_destroy(tls_session) == 0);
+    TEST_CHECK(conn->tls_session == NULL);
+
+    TEST_CHECK(flb_upstream_conn_release(conn) == 0);
+
+    /* pending_destroy must not double-free the already-destroyed session */
+    TEST_CHECK(flb_upstream_conn_pending_destroy(&upstream) == 0);
+    TEST_CHECK(backend_session.destroy_calls == 1);
+
+    flb_pipe_close(socket_pair[1]);
+
+#ifdef FLB_SYSTEM_WINDOWS
+    WSACleanup();
+#endif
+}
+
 #endif
 
 TEST_LIST = {
 #ifdef FLB_HAVE_TLS
     {"prepare_destroy_conn_marks_tls_session_stale", test_prepare_destroy_conn_marks_tls_session_stale},
+    {"tls_session_destroy_no_double_free", test_tls_session_destroy_no_double_free},
 #endif
     {0}
 };