can: test size of struct sockaddr in sendmsg

This patch makes the CAN socket code conform to the manpage of sendmsg.
Signed-off-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/can/bcm.c

@@ -1256,6 +1256,9 @@ static int bcm_sendmsg(struct kiocb *iocb, struct socket *sock,
 		struct sockaddr_can *addr =
 			(struct sockaddr_can *)msg->msg_name;
 
+		if (msg->msg_namelen < sizeof(*addr))
+			return -EINVAL;
+
 		if (addr->can_family != AF_CAN)
 			return -EINVAL;
 

net/can/raw.c

@@ -649,6 +649,9 @@ static int raw_sendmsg(struct kiocb *iocb, struct socket *sock,
 		struct sockaddr_can *addr =
 			(struct sockaddr_can *)msg->msg_name;
 
+		if (msg->msg_namelen < sizeof(*addr))
+			return -EINVAL;
+
 		if (addr->can_family != AF_CAN)
 			return -EINVAL;