mptcp: generate subflow hmac after mptcp_finish_join()

For outgoing subflow join, when recv SYNACK, in subflow_finish_connect(), the mptcp_finish_join() may return false in some cases, and send a RESET to remote, and no local hmac is required. So generate subflow hmac after mptcp_finish_join(). Fixes: ec3edaa ("mptcp: Add handling of outgoing MP_JOIN requests") Reviewed-by: Mat Martineau <[email protected]> Signed-off-by: Jianguo Wu <[email protected]>
multipath-tcp · May 19, 2021 · 50cb3a6 · 50cb3a6
1 parent 34514f0
commit 50cb3a6
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
@@ -430,15 +430,15 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
 			goto do_reset;
 		}
 
+		if (!mptcp_finish_join(sk))
+			goto do_reset;
+
 		subflow_generate_hmac(subflow->local_key, subflow->remote_key,
 				      subflow->local_nonce,
 				      subflow->remote_nonce,
 				      hmac);
 		memcpy(subflow->hmac, hmac, MPTCPOPT_HMAC_LEN);
 
-		if (!mptcp_finish_join(sk))
-			goto do_reset;
-
 		subflow->mp_join = 1;
 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX);