Fix: sessiond: event, filter expression, bytecode, exclusions might leak

Reported by Coverity:

    CID 1475803: Resource leak (RESOURCE_LEAK)
    Variable filter_expression going out of scope leaks the storage it points to.

    CID 1475816: Resource leak (RESOURCE_LEAK)
    Variable exclusions going out of scope leaks the storage it points to.

    CID 1475817: Resource leak (RESOURCE_LEAK)
    Variable bytecode going out of scope leaks the storage it points to.

    CID 1475820: Resource leak (RESOURCE_LEAK)
    Variable event going out of scope leaks the storage it points to.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I705e3cc1a1894af52d6ddeee94798a887dc82bba

diff --git a/src/bin/lttng-sessiond/client.cpp b/src/bin/lttng-sessiond/client.cpp
index 69a6497ee326d48bd64012e60697dbfb1fcbff90..7fd9d0b0ed4d4db0ec10a7d7000472fb754a5246 100644 (file)
--- a/src/bin/lttng-sessiond/client.cpp
+++ b/src/bin/lttng-sessiond/client.cpp
@@ -763,6 +763,10 @@ static enum lttng_error_code receive_lttng_event(struct command_ctx *cmd_ctx,
        ssize_t sock_recv_len;
        enum lttng_error_code ret_code;
        struct lttng_payload event_payload;
+       struct lttng_event *local_event = NULL;
+       char *local_filter_expression = NULL;
+       struct lttng_bytecode *local_bytecode = NULL;
+       struct lttng_event_exclusion *local_exclusion = NULL;
 
        lttng_payload_init(&event_payload);
        if (cmd_ctx->lsm.cmd_type == LTTNG_ENABLE_EVENT) {
@@ -810,23 +814,45 @@ static enum lttng_error_code receive_lttng_event(struct command_ctx *cmd_ctx,
 
        /* Deserialize event. */
        {
+               ssize_t len;
                struct lttng_payload_view event_view =
                                lttng_payload_view_from_payload(
                                                &event_payload, 0, -1);
 
-               if (lttng_event_create_from_payload(&event_view, out_event,
-                                   out_exclusion, out_filter_expression,
-                                   out_bytecode) != event_len) {
-                       ERR("Invalid event received as part of command payload");
+               len = lttng_event_create_from_payload(&event_view, &local_event,
+                                   &local_exclusion, &local_filter_expression,
+                                   &local_bytecode);
+
+               if (len < 0) {
+                       ERR("Failed to create an event from the received buffer");
+                       ret_code = LTTNG_ERR_INVALID_PROTOCOL;
+                       goto end;
+               }
+
+               if (len != event_len) {
+                       ERR("Userspace probe location from the received buffer is not the advertised length: header length = %zu" PRIu32 ", payload length = %zd", event_len, len);
                        ret_code = LTTNG_ERR_INVALID_PROTOCOL;
                        goto end;
                }
        }
 
+       *out_event = local_event;
+       *out_exclusion = local_exclusion;
+       *out_filter_expression = local_filter_expression;
+       *out_bytecode = local_bytecode;
+       local_event = NULL;
+       local_exclusion = NULL;
+       local_filter_expression = NULL;
+       local_bytecode = NULL;
+
        ret_code = LTTNG_OK;
 
 end:
        lttng_payload_reset(&event_payload);
+       lttng_event_destroy(local_event);
+       free(local_filter_expression);
+       free(local_bytecode);
+       free(local_exclusion);
        return ret_code;
 }