Fix: illegal memory access in disable_event

Found by Coverity:
CID 1243016 (#1 of 1): Buffer not null terminated
(BUFFER_SIZE_WARNING)14. buffer_size_warning: Calling strncpy with a
maximum size argument of 256 bytes on destination array msg.name of size
256 bytes might leave the destination string unterminated.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
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 c0b8a218b5acb0ef3cc33d53e2df2a805b01d7fc..9935e06121005baa69d444559ce87b09899ce2de 100644 (file)
--- a/src/bin/lttng-sessiond/agent.c
+++ b/src/bin/lttng-sessiond/agent.c
@@ -392,14 +392,17 @@ static int disable_event(struct agent_app *app, struct agent_event *event)
                        app->pid, app->sock->fd);
 
        data_size = sizeof(msg);
+       memset(&msg, 0, sizeof(msg));
+       if (lttng_strncpy(msg.name, event->name, sizeof(msg.name))) {
+               ret = LTTNG_ERR_INVALID;
+               goto error;
+       }
 
        ret = send_header(app->sock, data_size, AGENT_CMD_DISABLE, 0);
        if (ret < 0) {
                goto error_io;
        }
 
-       memset(&msg, 0, sizeof(msg));
-       strncpy(msg.name, event->name, sizeof(msg.name));
        ret = send_payload(app->sock, &msg, sizeof(msg));
        if (ret < 0) {
                goto error_io;