From: Paolo Abeni Date: Wed, 31 May 2023 19:37:08 +0000 (-0700) Subject: mptcp: fix active subflow finalization X-Git-Tag: v6.6.7~2747^2~1^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=55b47ca7d80814ceb63d64e032e96cd6777811e5;p=platform%2Fkernel%2Flinux-starfive.git mptcp: fix active subflow finalization Active subflow are inserted into the connection list at creation time. When the MPJ handshake completes successfully, a new subflow creation netlink event is generated correctly, but the current code wrongly avoid initializing a couple of subflow data. The above will cause misbehavior on a few exceptional events: unneeded mptcp-level retransmission on msk-level sequence wrap-around and infinite mapping fallback even when a MPJ socket is present. Address the issue factoring out the needed initialization in a new helper and invoking the latter from __mptcp_finish_join() time for passive subflow and from mptcp_finish_join() for active ones. Fixes: 0530020a7c8f ("mptcp: track and update contiguous data status") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau Signed-off-by: Jakub Kicinski --- diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index af54a87..67311e7 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -825,6 +825,13 @@ void mptcp_data_ready(struct sock *sk, struct sock *ssk) mptcp_data_unlock(sk); } +static void mptcp_subflow_joined(struct mptcp_sock *msk, struct sock *ssk) +{ + mptcp_subflow_ctx(ssk)->map_seq = READ_ONCE(msk->ack_seq); + WRITE_ONCE(msk->allow_infinite_fallback, false); + mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC); +} + static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk) { struct sock *sk = (struct sock *)msk; @@ -839,6 +846,7 @@ static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk) mptcp_sock_graft(ssk, sk->sk_socket); mptcp_sockopt_sync_locked(msk, ssk); + mptcp_subflow_joined(msk, ssk); return true; } @@ -3485,14 +3493,16 @@ bool mptcp_finish_join(struct sock *ssk) return false; } - if (!list_empty(&subflow->node)) - goto out; + /* active subflow, already present inside the conn_list */ + if (!list_empty(&subflow->node)) { + mptcp_subflow_joined(msk, ssk); + return true; + } if (!mptcp_pm_allow_new_subflow(msk)) goto err_prohibited; - /* active connections are already on conn_list. - * If we can't acquire msk socket lock here, let the release callback + /* If we can't acquire msk socket lock here, let the release callback * handle it */ mptcp_data_lock(parent); @@ -3515,11 +3525,6 @@ err_prohibited: return false; } - subflow->map_seq = READ_ONCE(msk->ack_seq); - WRITE_ONCE(msk->allow_infinite_fallback, false); - -out: - mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC); return true; }