From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Sat, 15 Nov 2014 05:20:15 +0000 (-0500)
Subject: Fix: Ambiguous agent event filter bytecode ownership
X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=commitdiff_plain;h=971da06a61170301dc28c2203ef0679c3024e21d

Fix: Ambiguous agent event filter bytecode ownership

A shared ownership of the filter bytecode between UST events
and Agent event led to a leak in cmd_enable_event() which was
fixed previously. However, that fix introduced a bug which
passed NULL to the agent event creation function.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/bin/lttng-sessiond/agent.c b/src/bin/lttng-sessiond/agent.c
index eb3ab1a44..1cd70e8c5 100644
--- a/src/bin/lttng-sessiond/agent.c
+++ b/src/bin/lttng-sessiond/agent.c
@@ -913,6 +913,7 @@ void agent_destroy_event(struct agent_event *event)
 {
 	assert(event);
 
+	free(event->filter);
 	free(event);
 }
 
diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 8c13c2dd6..2dcc52b7a 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -1604,11 +1604,30 @@ int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
 			assert(0);
 		}
 
-		ret = cmd_enable_event(session, &tmp_dom, (char *) default_chan_name,
-			&uevent, filter_expression, filter, NULL, wpipe);
-		/* We have passed ownership */
-		filter_expression = NULL;
-		filter = NULL;
+		{
+			struct lttng_filter_bytecode *filter_copy = NULL;
+
+			if (filter) {
+				filter_copy = zmalloc(
+					sizeof(struct lttng_filter_bytecode)
+					+ filter->len);
+				if (!filter_copy) {
+					goto error;
+				}
+
+				memcpy(filter_copy, filter,
+					sizeof(struct lttng_filter_bytecode)
+					+ filter->len);
+			}
+
+			ret = cmd_enable_event(session, &tmp_dom,
+					(char *) default_chan_name,
+					&uevent, filter_expression, filter_copy,
+					NULL, wpipe);
+			/* We have passed ownership */
+			filter_expression = NULL;
+		}
+
 		if (ret != LTTNG_OK && ret != LTTNG_ERR_UST_EVENT_ENABLED) {
 			goto error;
 		}
@@ -1616,8 +1635,10 @@ int cmd_enable_event(struct ltt_session *session, struct lttng_domain *domain,
 		/* The wild card * means that everything should be enabled. */
 		if (strncmp(event->name, "*", 1) == 0 && strlen(event->name) == 1) {
 			ret = event_agent_enable_all(usess, agt, event, filter);
+			filter = NULL;
 		} else {
 			ret = event_agent_enable(usess, agt, event, filter);
+			filter = NULL;
 		}
 		if (ret != LTTNG_OK) {
 			goto error;