1 files changed, 14 insertions, 5 deletions

diff --git a/net/dccp/output.c b/net/dccp/output.c
index 809d803d5006..22a618af4893 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -175,7 +175,7 @@ unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu)
          * make it a multiple of 4
          */
 
-        cur_mps -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4;
+        cur_mps -= roundup(5 + 6 + 10 + 6 + 6 + 6, 4);
 
         /* And store cached results */
         icsk->icsk_pmtu_cookie = pmtu;
@@ -339,10 +339,12 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
         DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE;
         DCCP_SKB_CB(skb)->dccpd_seq  = dreq->dreq_iss;
 
-        if (dccp_insert_options_rsk(dreq, skb)) {
-                kfree_skb(skb);
-                return NULL;
-        }
+        /* Resolve feature dependencies resulting from choice of CCID */
+        if (dccp_feat_server_ccid_dependencies(dreq))
+                goto response_failed;
+
+        if (dccp_insert_options_rsk(dreq, skb))
+                goto response_failed;
 
         /* Build and checksum header */
         dh = dccp_zeroed_hdr(skb, dccp_header_size);
@@ -363,6 +365,9 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
         inet_rsk(req)->acked = 1;
         DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
         return skb;
+response_failed:
+        kfree_skb(skb);
+        return NULL;
 }
 
 EXPORT_SYMBOL_GPL(dccp_make_response);
@@ -469,6 +474,10 @@ int dccp_connect(struct sock *sk)
         struct sk_buff *skb;
         struct inet_connection_sock *icsk = inet_csk(sk);
 
+        /* do not connect if feature negotiation setup fails */
+        if (dccp_feat_finalise_settings(dccp_sk(sk)))
+                return -EPROTO;
+
         dccp_connect_init(sk);
 
         skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation);