diff --git a/drivers/isdn/mISDN/socket.c b/drivers/isdn/mISDN/socket.c
index 3232206406b15bcdba06b39b837545307902d3e1..7446d8b4282d58cee32d435c930c23b1b43092a4 100644
--- a/drivers/isdn/mISDN/socket.c
+++ b/drivers/isdn/mISDN/socket.c
@@ -392,6 +392,7 @@ data_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 		if (dev) {
 			struct mISDN_devinfo di;
 
+			memset(&di, 0, sizeof(di));
 			di.id = dev->id;
 			di.Dprotocols = dev->Dprotocols;
 			di.Bprotocols = dev->Bprotocols | get_all_Bprotocols();
@@ -672,6 +673,7 @@ base_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 		if (dev) {
 			struct mISDN_devinfo di;
 
+			memset(&di, 0, sizeof(di));
 			di.id = dev->id;
 			di.Dprotocols = dev->Dprotocols;
 			di.Bprotocols = dev->Bprotocols | get_all_Bprotocols();