1 files changed, 21 insertions, 12 deletions

diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index db5fc2440a23..e7e0b9bc2a43 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -202,7 +202,9 @@ static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req
         security_req_classify_flow(req, flowi6_to_flowi(&fl6));
 
 
-        final_p = fl6_update_dst(&fl6, np->opt, &final);
+        rcu_read_lock();
+        final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final);
+        rcu_read_unlock();
 
         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
         if (IS_ERR(dst)) {
@@ -219,7 +221,10 @@ static int dccp_v6_send_response(const struct sock *sk, struct request_sock *req
                                                          &ireq->ir_v6_loc_addr,
                                                          &ireq->ir_v6_rmt_addr);
                 fl6.daddr = ireq->ir_v6_rmt_addr;
-                err = ip6_xmit(sk, skb, &fl6, np->opt, np->tclass);
+                rcu_read_lock();
+                err = ip6_xmit(sk, skb, &fl6, rcu_dereference(np->opt),
+                               np->tclass);
+                rcu_read_unlock();
                 err = net_xmit_eval(err);
         }
 
@@ -387,6 +392,7 @@ static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
         struct inet_request_sock *ireq = inet_rsk(req);
         struct ipv6_pinfo *newnp;
         const struct ipv6_pinfo *np = inet6_sk(sk);
+        struct ipv6_txoptions *opt;
         struct inet_sock *newinet;
         struct dccp6_sock *newdp6;
         struct sock *newsk;
@@ -488,13 +494,15 @@ static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
          * Yes, keeping reference count would be much more clever, but we make
          * one more one thing there: reattach optmem to newsk.
          */
-        if (np->opt != NULL)
-                newnp->opt = ipv6_dup_options(newsk, np->opt);
-
+        opt = rcu_dereference(np->opt);
+        if (opt) {
+                opt = ipv6_dup_options(newsk, opt);
+                RCU_INIT_POINTER(newnp->opt, opt);
+        }
         inet_csk(newsk)->icsk_ext_hdr_len = 0;
-        if (newnp->opt != NULL)
-                inet_csk(newsk)->icsk_ext_hdr_len = (newnp->opt->opt_nflen +
-                                                     newnp->opt->opt_flen);
+        if (opt)
+                inet_csk(newsk)->icsk_ext_hdr_len = opt->opt_nflen +
+                                                    opt->opt_flen;
 
         dccp_sync_mss(newsk, dst_mtu(dst));
 
@@ -757,6 +765,7 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
         struct ipv6_pinfo *np = inet6_sk(sk);
         struct dccp_sock *dp = dccp_sk(sk);
         struct in6_addr *saddr = NULL, *final_p, final;
+        struct ipv6_txoptions *opt;
         struct flowi6 fl6;
         struct dst_entry *dst;
         int addr_type;
@@ -856,7 +865,8 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
         fl6.fl6_sport = inet->inet_sport;
         security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));
 
-        final_p = fl6_update_dst(&fl6, np->opt, &final);
+        opt = rcu_dereference_protected(np->opt, sock_owned_by_user(sk));
+        final_p = fl6_update_dst(&fl6, opt, &final);
 
         dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
         if (IS_ERR(dst)) {
@@ -876,9 +886,8 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
         __ip6_dst_store(sk, dst, NULL, NULL);
 
         icsk->icsk_ext_hdr_len = 0;
-        if (np->opt != NULL)
-                icsk->icsk_ext_hdr_len = (np->opt->opt_flen +
-                                          np->opt->opt_nflen);
+        if (opt)
+                icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
 
         inet->inet_dport = usin->sin6_port;