From: David Goulet <david.goulet@polymtl.ca>
Date: Tue, 8 Nov 2011 19:30:20 +0000 (-0500)
Subject: Fix possible NULL pointer dereference
X-Git-Tag: v2.0-pre15~143
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=1f3580c7152869e3827f475a713a9567f8357bc8;p=lttng-tools.git

Fix possible NULL pointer dereference

Signed-off-by: David Goulet <david.goulet@polymtl.ca>
---

diff --git a/lttng-sessiond/ust-app.c b/lttng-sessiond/ust-app.c
index b2c73ffed..72e3aeef2 100644
--- a/lttng-sessiond/ust-app.c
+++ b/lttng-sessiond/ust-app.c
@@ -859,10 +859,16 @@ void ust_app_global_update(struct ltt_ust_session *usess, int sock)
 	struct lttng_ust_object_data *obj_event;
 	struct lttng_ust_channel_attr uattr;
 
+	rcu_read_lock();
+
+	if (usess == NULL) {
+		DBG2("No UST session on global update. Returning");
+		goto error;
+	}
+
 	DBG2("UST app global update for app sock %d for session uid %d", sock,
 			usess->uid);
 
-	rcu_read_lock();
 	app = find_app_by_sock(sock);
 	if (app == NULL) {
 		ERR("Failed to update app sock %d", sock);