[PATCH 4.9 047/101] tipc: use destination length for copy string

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Guoqing Jiang <gqjiang@xxxxxxxx>

commit 29e270fc32192e7729057963ae7120663856c93e upstream.

Got below warning with gcc 8.2 compiler.

net/tipc/topsrv.c: In function âtipc_topsrv_startâ:
net/tipc/topsrv.c:660:2: warning: âstrncpyâ specified bound depends on the length of the source argument [-Wstringop-overflow=]
  strncpy(srv->name, name, strlen(name) + 1);
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
net/tipc/topsrv.c:660:27: note: length computed here
  strncpy(srv->name, name, strlen(name) + 1);
                           ^~~~~~~~~~~~
So change it to correct length and use strscpy.

Signed-off-by: Guoqing Jiang <gqjiang@xxxxxxxx>
Acked-by: Ying Xue <ying.xue@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/tipc/subscr.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/tipc/subscr.c
+++ b/net/tipc/subscr.c
@@ -389,7 +389,7 @@ int tipc_topsrv_start(struct net *net)
 	topsrv->tipc_conn_new		= tipc_subscrb_connect_cb;
 	topsrv->tipc_conn_release	= tipc_subscrb_release_cb;
 
-	strncpy(topsrv->name, name, strlen(name) + 1);
+	strscpy(topsrv->name, name, sizeof(topsrv->name));
 	tn->topsrv = topsrv;
 	atomic_set(&tn->subscription_count, 0);