Fix: lttng-sessiond: event_context might leak

[lttng-tools.git] / src / bin / lttng-sessiond / client.cpp

diff --git a/src/bin/lttng-sessiond/client.cpp b/src/bin/lttng-sessiond/client.cpp
index abd26fcb96f755b9687cfa2cdb23342e387d2bff..69a6497ee326d48bd64012e60697dbfb1fcbff90 100644 (file)
--- a/src/bin/lttng-sessiond/client.cpp
+++ b/src/bin/lttng-sessiond/client.cpp
@@ -842,6 +842,7 @@ static enum lttng_error_code receive_lttng_event_context(
        ssize_t sock_recv_len;
        enum lttng_error_code ret_code;
        struct lttng_payload event_context_payload;
+       struct lttng_event_context *context = NULL;
 
        lttng_payload_init(&event_context_payload);
 
@@ -864,22 +865,33 @@ static enum lttng_error_code receive_lttng_event_context(
 
        /* Deserialize event. */
        {
+               ssize_t len;
                struct lttng_payload_view event_context_view =
                                lttng_payload_view_from_payload(
                                                &event_context_payload, 0, -1);
 
-               if (lttng_event_context_create_from_payload(
-                               &event_context_view, out_event_context) !=
-                               event_context_len) {
-                       ERR("Invalid event context received as part of command payload");
+               len = lttng_event_context_create_from_payload(
+                               &event_context_view, &context);
+
+               if (len < 0) {
+                       ERR("Failed to create a event context from the received buffer");
+                       ret_code = LTTNG_ERR_INVALID_PROTOCOL;
+                       goto end;
+               }
+
+               if (len != event_context_len) {
+                       ERR("Event context from the received buffer is not the advertised length: expected length = %zu, payload length = %zd", event_context_len, len);
                        ret_code = LTTNG_ERR_INVALID_PROTOCOL;
                        goto end;
                }
        }
 
+       *out_event_context = context;
+       context = NULL;
        ret_code = LTTNG_OK;
 
 end:
+       lttng_event_context_destroy(context);
        lttng_payload_reset(&event_context_payload);
        return ret_code;
 }
@@ -1353,7 +1365,7 @@ skip_domain:
        switch (cmd_ctx->lsm.cmd_type) {
        case LTTNG_ADD_CONTEXT:
        {
-               struct lttng_event_context *event_context;
+               struct lttng_event_context *event_context = NULL;
                const enum lttng_error_code ret_code =
                        receive_lttng_event_context(
                                cmd_ctx, *sock, sock_error, &event_context);
@@ -1642,30 +1654,31 @@ skip_domain:
        }
        case LTTNG_LIST_TRACEPOINT_FIELDS:
        {
-               struct lttng_event_field *fields;
-               ssize_t nb_fields;
+               enum lttng_error_code ret_code;
+               size_t original_payload_size;
+               size_t payload_size;
+               const size_t command_header_size = sizeof(struct lttcomm_list_command_header);
+
+               ret = setup_empty_lttng_msg(cmd_ctx);
+               if (ret) {
+                       ret = LTTNG_ERR_NOMEM;
+                       goto setup_error;
+               }
+
+               original_payload_size = cmd_ctx->reply_payload.buffer.size;
 
                session_lock_list();
-               nb_fields = cmd_list_tracepoint_fields(cmd_ctx->lsm.domain.type,
-                               &fields);
+               ret_code = cmd_list_tracepoint_fields(
+                               cmd_ctx->lsm.domain.type, &cmd_ctx->reply_payload);
                session_unlock_list();
-               if (nb_fields < 0) {
-                       /* Return value is a negative lttng_error_code. */
-                       ret = -nb_fields;
+               if (ret_code != LTTNG_OK) {
+                       ret = (int) ret_code;
                        goto error;
                }
 
-               /*
-                * Setup lttng message with payload size set to the event list size in
-                * bytes and then copy list into the llm payload.
-                */
-               ret = setup_lttng_msg_no_cmd_header(cmd_ctx, fields,
-                               sizeof(struct lttng_event_field) * nb_fields);
-               free(fields);
-
-               if (ret < 0) {
-                       goto setup_error;
-               }
+               payload_size = cmd_ctx->reply_payload.buffer.size -
+                               command_header_size - original_payload_size;
+               update_lttng_msg(cmd_ctx, command_header_size, payload_size);
 
                ret = LTTNG_OK;
                break;