From: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Date: Tue, 18 Feb 2020 01:05:22 +0000 (-0500)
Subject: Fix: relayd: use of relay_session ref count before initialization
X-Git-Tag: v2.13.0-rc1~750
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=19efdf659e29ec34a27c304ccbf7ad6ff8e26337

Fix: relayd: use of relay_session ref count before initialization

The relay_session's reference count is used before it is initialized
on multiple code paths of session_create(). The initialization of the
reference count, mutexes, and intrusive data structure nodes are
initialized earlier to make their use safe in the event of an error.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I1be53ad88a3e783b85b4c568527df1a75ce58d3a
---

diff --git a/src/bin/lttng-relayd/session.c b/src/bin/lttng-relayd/session.c
index daae9a55b..f40f70965 100644
--- a/src/bin/lttng-relayd/session.c
+++ b/src/bin/lttng-relayd/session.c
@@ -316,6 +316,17 @@ struct relay_session *session_create(const char *session_name,
 		PERROR("Failed to allocate session");
 		goto error;
 	}
+
+	pthread_mutex_lock(&last_relay_session_id_lock);
+	session->id = ++last_relay_session_id;
+	pthread_mutex_unlock(&last_relay_session_id_lock);
+
+	lttng_ht_node_init_u64(&session->session_n, session->id);
+	urcu_ref_init(&session->ref);
+	CDS_INIT_LIST_HEAD(&session->recv_list);
+	pthread_mutex_init(&session->lock, NULL);
+	pthread_mutex_init(&session->recv_list_lock, NULL);
+
 	if (lttng_strncpy(session->session_name, session_name,
 			sizeof(session->session_name))) {
 	        WARN("Session name exceeds maximal allowed length");
@@ -342,17 +353,8 @@ struct relay_session *session_create(const char *session_name,
 		goto error;
 	}
 
-	pthread_mutex_lock(&last_relay_session_id_lock);
-	session->id = ++last_relay_session_id;
-	pthread_mutex_unlock(&last_relay_session_id_lock);
-
 	session->major = major;
 	session->minor = minor;
-	lttng_ht_node_init_u64(&session->session_n, session->id);
-	urcu_ref_init(&session->ref);
-	CDS_INIT_LIST_HEAD(&session->recv_list);
-	pthread_mutex_init(&session->lock, NULL);
-	pthread_mutex_init(&session->recv_list_lock, NULL);
 
 	session->live_timer = live_timer;
 	session->snapshot = snapshot;