From nobody Fri Dec 13 12:12:49 2024 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 BA44C811E4 for ; Wed, 24 Jan 2024 21:36:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706132217; cv=none; b=av/o0KNWePefqprt4za/QhHXdOtpcCdGD2ni2+wpHXEm8CGEomlG/TmCZ3UalVASRloien6aw7gs0jFtmrFPUxyMsPjNHSuyyQ2zD6nNtgRzJrmYpIs8OPgxgV6Ql/65V+LcyZpcL1EeH735o9E4N3hFN0z3LQRfNx7qpvOJuY4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706132217; c=relaxed/simple; bh=cpkUMNCixjYuP8U8bjfCrJkCjl+7BvNRQl66qLhf+L4=; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type; b=CJINSPdWlTsLm8pS8f8YQBEEvuIP07K1fdZHW8ZjHELUwIm7RaDopC7+C/TKuCANTL5EDYHgWktZRZ5kww/MdZNv+q2iyuCvVxd3JCzWgvaFfe9P+nKkHNowxps+w0gcDxMbXC8dEoKQPULpre0cv6NiF3VvgSZ2N+q3a5bvjRc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=ajyeX1Ux; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ajyeX1Ux" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1706132214; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=fjxcHb69xyhYSiWyhhPL+8HDEtm3imBIJfJQfe+osTM=; b=ajyeX1Ux3vr4Ug4FmNooLLAOX2oJmXE8cmUrrOd1/tvzP+sLAxQXINg+/xgnavUBgT7CGx bAqWYFKMUPSZn5w3oA254VBteivWGP0g1Tg+WeV2cGCgy9sXNBFnHY9ZYaYbRA75cS1Kxs TJ3AF+hi/ZwdhlvbLEnfWWYtPeIKkYk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-17-23OcJpFlNPm_N_bPO3CkPg-1; Wed, 24 Jan 2024 16:36:52 -0500 X-MC-Unique: 23OcJpFlNPm_N_bPO3CkPg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 939268489A0 for ; Wed, 24 Jan 2024 21:36:52 +0000 (UTC) Received: from gerbillo.redhat.com (unknown [10.45.225.29]) by smtp.corp.redhat.com (Postfix) with ESMTP id 237A21121306 for ; Wed, 24 Jan 2024 21:36:51 +0000 (UTC) From: Paolo Abeni To: mptcp@lists.linux.dev Subject: [PATCH mptcp-net] mptcp: really cope with fastopen race. Date: Wed, 24 Jan 2024 22:36:44 +0100 Message-ID: <02fe7afaec6fac65fc2da5922efe25d6ebdebc88.1706132185.git.pabeni@redhat.com> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8"; x-default="true" Fastopen and PM-trigger subflow shutdown can race, as reported by syzkaller. In my first attempt to close such race, I missed the fact that the subflow status can change again before the subflow_state_change callback is invoked. Address the issue additionally copying with all the states directly reachable from TCP_FIN_WAIT1. Fixes: 1e777f39b4d7 ("mptcp: add MSG_FASTOPEN sendmsg flag support") Fixes: 4fd19a307016 ("mptcp: fix inconsistent state on fastopen race") Reported-by: syzbot+c53d4d3ddb327e80bc51@syzkaller.appspotmail.com Signed-off-by: Paolo Abeni Reported-by: syzbot+732ab7be796ec0d104ac@syzkaller.appspotmail.com Reviewed-by: Mat Martineau --- net/mptcp/protocol.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 4a32d3d11fb6..de04b97e8dd1 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -1171,7 +1171,8 @@ static inline bool subflow_simultaneous_connect(struc= t sock *sk) { struct mptcp_subflow_context *subflow =3D mptcp_subflow_ctx(sk); =20 - return (1 << sk->sk_state) & (TCPF_ESTABLISHED | TCPF_FIN_WAIT1) && + return (1 << sk->sk_state) & + (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 | TCPF_CLOSING= ) && is_active_ssk(subflow) && !subflow->conn_finished; } --=20 2.43.0