diff --cc net/mptcp/protocol.c
index 7833a49f6214,9df4eaddfd48..000000000000
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@@ -3242,25 -3204,18 +3247,25 @@@ struct sock *mptcp_sk_clone_init(const 
  
  	__mptcp_init_sock(nsk);
  
 +#if IS_ENABLED(CONFIG_MPTCP_IPV6)
 +	if (nsk->sk_family == AF_INET6)
 +		mptcp_copy_ip6_options(nsk, sk);
 +	else
 +#endif
 +		mptcp_copy_ip_options(nsk, sk);
 +
  	msk = mptcp_sk(nsk);
- 	msk->local_key = subflow_req->local_key;
- 	msk->token = subflow_req->token;
+ 	WRITE_ONCE(msk->local_key, subflow_req->local_key);
+ 	WRITE_ONCE(msk->token, subflow_req->token);
  	msk->in_accept_queue = 1;
  	WRITE_ONCE(msk->fully_established, false);
  	if (mp_opt->suboptions & OPTION_MPTCP_CSUMREQD)
  		WRITE_ONCE(msk->csum_enabled, true);
  
- 	msk->write_seq = subflow_req->idsn + 1;
- 	msk->snd_nxt = msk->write_seq;
- 	msk->snd_una = msk->write_seq;
- 	msk->wnd_end = msk->snd_nxt + tcp_sk(ssk)->snd_wnd;
+ 	WRITE_ONCE(msk->write_seq, subflow_req->idsn + 1);
+ 	WRITE_ONCE(msk->snd_nxt, msk->write_seq);
+ 	WRITE_ONCE(msk->snd_una, msk->write_seq);
 -	WRITE_ONCE(msk->wnd_end, msk->snd_nxt + req->rsk_rcv_wnd);
++	WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd);
  	msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq;
  	mptcp_init_sched(msk, mptcp_sk(sk)->sched);