From: Jianguo Wu <wujianguo@xxxxxxxxxxxxxxx> [ Upstream commit 0a4d8e96e4fd687af92b961d5cdcea0fdbde05fe ] 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: ec3edaa7ca6c ("mptcp: Add handling of outgoing MP_JOIN requests") Signed-off-by: Jianguo Wu <wujianguo@xxxxxxxxxxxxxxx> Signed-off-by: Mat Martineau <mathew.j.martineau@xxxxxxxxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/mptcp/subflow.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index d6d8ad4f918e..189139b8d401 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -409,15 +409,15 @@ 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); -- 2.30.2