netrom: copy_datagram_iovec can fail

Check for an error from this and if so bail properly.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netrom/af_netrom.c

@@ -1169,7 +1169,12 @@ static int nr_recvmsg(struct kiocb *iocb, struct socket *sock,
 		msg->msg_flags |= MSG_TRUNC;
 	}
 
-	skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	er = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	if (er < 0) {
+		skb_free_datagram(sk, skb);
+		release_sock(sk);
+		return er;
+	}
 
 	if (sax != NULL) {
 		sax->sax25_family = AF_NETROM;