From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1CF3314F9C8; Tue, 20 Feb 2024 21:34:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708464875; cv=none; b=b/wCtCVXGJEziKVLoSrMDwXnJwpxbkmZcMjru18NUrcheQOFGH4g/PoyLH+43G5VmcR5Ksx5llvDc389sOFKT8EUUTxMi6ItTDbteffxdRjvxEMWpg/ZExYd9gTlBT/YZmjidrzRfEDMdUqA90yrU1YPAVJnGJSyOOuWBIhdN58= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708464875; c=relaxed/simple; bh=bwEEXl8PIEN030VYvXpfD5VTrPthOhBvxEoGvyt+aE4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XCuLAF6znPo9FQPTLo2IqaczkQZmakMg02YCC5vlfRIxTIY/jDoueQUbW45QTQysatL0T1IlQ1FMTWyXt5w4C/rwvckrdlZfXiQ71To1OvxBrBjD+Hr1v9WPfS5v51B63OVauPp0TKsKW1WErITiyacWh0ecUQxunStSVT8tNg4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JjTFDUJ8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JjTFDUJ8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7EE88C433F1; Tue, 20 Feb 2024 21:34:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1708464875; bh=bwEEXl8PIEN030VYvXpfD5VTrPthOhBvxEoGvyt+aE4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JjTFDUJ8uzterIMzYciL85Dmq7GhpT+mpxwsDL7b0cxCqzIIvn3BMvhQuXI+sPPaj JwBGeY32oIY1pP2f2gLClBw6QKSWgzbMC+peTsYKW+97t5a5U8cmu8y3REmns4+kpH ds0BEB28ekMGr7fWvjqKHNWXhHzR+NBDB/4Ylb5s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paolo Abeni , Mat Martineau , "Matthieu Baerts (NGI0)" , "David S. Miller" Subject: [PATCH 6.7 124/309] mptcp: fix rcv space initialization Date: Tue, 20 Feb 2024 21:54:43 +0100 Message-ID: <20240220205637.044426504@linuxfoundation.org> X-Mailer: git-send-email 2.43.2 In-Reply-To: <20240220205633.096363225@linuxfoundation.org> References: <20240220205633.096363225@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni commit 013e3179dbd2bc756ce1dd90354abac62f65b739 upstream. mptcp_rcv_space_init() is supposed to happen under the msk socket lock, but active msk socket does that without such protection. Leverage the existing mptcp_propagate_state() helper to that extent. We need to ensure mptcp_rcv_space_init will happen before mptcp_rcv_space_adjust(), and the release_cb does not assure that: explicitly check for such condition. While at it, move the wnd_end initialization out of mptcp_rcv_space_init(), it never belonged there. Note that the race does not produce ill effect in practice, but change allows cleaning-up and defying better the locking model. Fixes: a6b118febbab ("mptcp: add receive buffer auto-tuning") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/mptcp/protocol.c | 10 ++++++---- net/mptcp/protocol.h | 3 ++- net/mptcp/subflow.c | 4 ++-- 3 files changed, 10 insertions(+), 7 deletions(-) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1977,6 +1977,9 @@ static void mptcp_rcv_space_adjust(struc if (copied <= 0) return; + if (!msk->rcvspace_init) + mptcp_rcv_space_init(msk, msk->first); + msk->rcvq_space.copied += copied; mstamp = div_u64(tcp_clock_ns(), NSEC_PER_USEC); @@ -3156,6 +3159,7 @@ static int mptcp_disconnect(struct sock msk->bytes_received = 0; msk->bytes_sent = 0; msk->bytes_retrans = 0; + msk->rcvspace_init = 0; WRITE_ONCE(sk->sk_shutdown, 0); sk_error_report(sk); @@ -3243,6 +3247,7 @@ void mptcp_rcv_space_init(struct mptcp_s { const struct tcp_sock *tp = tcp_sk(ssk); + msk->rcvspace_init = 1; msk->rcvq_space.copied = 0; msk->rcvq_space.rtt_us = 0; @@ -3253,8 +3258,6 @@ void mptcp_rcv_space_init(struct mptcp_s TCP_INIT_CWND * tp->advmss); if (msk->rcvq_space.space == 0) msk->rcvq_space.space = TCP_INIT_CWND * TCP_MSS_DEFAULT; - - WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd); } static struct sock *mptcp_accept(struct sock *ssk, int flags, int *err, @@ -3512,10 +3515,9 @@ void mptcp_finish_connect(struct sock *s WRITE_ONCE(msk->write_seq, subflow->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 + tcp_sk(ssk)->snd_wnd); mptcp_pm_new_connection(msk, ssk, 0); - - mptcp_rcv_space_init(msk, ssk); } void mptcp_sock_graft(struct sock *sk, struct socket *parent) --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -304,7 +304,8 @@ struct mptcp_sock { nodelay:1, fastopening:1, in_accept_queue:1, - free_first:1; + free_first:1, + rcvspace_init:1; struct work_struct work; struct sk_buff *ooo_last_skb; struct rb_root out_of_order_queue; --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -424,6 +424,8 @@ void __mptcp_sync_state(struct sock *sk, struct mptcp_sock *msk = mptcp_sk(sk); __mptcp_propagate_sndbuf(sk, msk->first); + if (!msk->rcvspace_init) + mptcp_rcv_space_init(msk, msk->first); if (sk->sk_state == TCP_SYN_SENT) { inet_sk_state_store(sk, state); sk->sk_state_change(sk); @@ -545,7 +547,6 @@ static void subflow_finish_connect(struc } } else if (mptcp_check_fallback(sk)) { fallback: - mptcp_rcv_space_init(msk, sk); mptcp_propagate_state(parent, sk); } return; @@ -1744,7 +1745,6 @@ static void subflow_state_change(struct msk = mptcp_sk(parent); if (subflow_simultaneous_connect(sk)) { mptcp_do_fallback(sk); - mptcp_rcv_space_init(msk, sk); pr_fallback(msk); subflow->conn_finished = 1; mptcp_propagate_state(parent, sk);