diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 671cd1413d59..85ec1cb7fd41 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -835,6 +835,8 @@ int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 			len = -EFAULT;
 			break;
 		}
+		if (flags & MSG_TRUNC)
+			len = skb->len;
 	found_fin_ok:
 		if (!(flags & MSG_PEEK))
 			sk_eat_skb(sk, skb, 0);