From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 4835540B6CF for ; Mon, 29 Jun 2026 13:15:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782738904; cv=none; b=TMCDmlUnqJUzCGMH1fy6PF5N3cs/Nxu3IOhvFKnYGq6nSyjHFpQP5Q944X2O7swaHKOPeWccs1nCXe3jGw2yiPm6fSa4SyNqJFBnWC+k/Nh8uWRDy9H8c5N9JoOaQIWh74C/vAktZK3/XgWNqYWQjauCZTP5NlTcotSjk07/7I4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782738904; c=relaxed/simple; bh=V+ip7hOaNxQN+PupY79i45O/+JJVNlH3/T229lk4eXI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=jCRglFeWuyyeGdFfWB7+myNiXMT0/nkT1aePIj1y0r/pkf0eM8SdWsCU0YsjnjrUAvDbLx+uXOuszju1ezHz3rvEmxAJwACQAHs1Cd3yEEiNxxPZowYCv9V8iWWHtA6KVTs593owv31gvv4MJnFBthL9dOC8WWffxQBopU5YF7A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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=DAO0MwtB; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=YF3y3nRg; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine 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="DAO0MwtB"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="YF3y3nRg" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1782738901; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SxtVeyiP7HimsNveV07yo+ZQVotxy5gp97RrKjEG4ko=; b=DAO0MwtBetxvn7P8gyekpyeQb4uhAfqt13YP4SdxlT3FGacqjo8s42oleXEBuISpHAW/TI 751K0VpZHq7HdaoUrHXqPGbZa+h639O5eHVXYiZoBrrc4tagtswN5YBsBuj1RlYsK6ZMMO T0bfzZw7g7nRiyztWQ0RHNqrEUPh/5E= Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-228-S17XBHTgPrWxkb6n3YxzTA-1; Mon, 29 Jun 2026 09:14:59 -0400 X-MC-Unique: S17XBHTgPrWxkb6n3YxzTA-1 X-Mimecast-MFC-AGG-ID: S17XBHTgPrWxkb6n3YxzTA_1782738899 Received: by mail-wr1-f72.google.com with SMTP id ffacd0b85a97d-473941177b0so725559f8f.1 for ; Mon, 29 Jun 2026 06:14:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1782738898; x=1783343698; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:content-language:from :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=SxtVeyiP7HimsNveV07yo+ZQVotxy5gp97RrKjEG4ko=; b=YF3y3nRgm0S6aEsOkrAxxEA7YY4Vj++oV9di+vC9qg32jxwFwjlyOP2mdYQeITpyBE dN6t0+bQnBLbeqKNhyBNjiINJ41MSLsoMFXvKRONwz61O6tBOqrHRBURgd2323ItOrs9 HHJqjd+9SBsK5VRdqdPqXcD2TqRq5BAWOj9rMcRnVlORK3IWEMdEvbayBDahbln7TCPN U+AqD6eiS4LekN+dPTF94qz2H+QoLIruG2GjwI+J9f7Yhl6ekouFtZrSH06Fz2syB2VE KyOUPOu0biE6rf+1r74PfsHyxMazy8FF3TJ/4VmVJbEI/ln+SndFlpvPRhBvLweKT8yS 2M8g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782738898; x=1783343698; h=content-transfer-encoding:in-reply-to:content-language:from :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=SxtVeyiP7HimsNveV07yo+ZQVotxy5gp97RrKjEG4ko=; b=JHrU6PYA6ctskpFRwziWpJSBs7IxlsTp0FMlXGEtzvJmbDkXYPIpRGq3MJMzf9OkJf 7qucU39+3MGp7mRwUI9s5p7v7w/rwbj17CwwlM3272vBDs23QOD7uKT7yRu/4+GWHA2+ fHu9mEeRXPjDwbO0nv6EUC0RlZgzNBHuIQZJiGQJrpycHuEK9qgvjm5lV2LpvUHE3OZs Vm6eW+MPp37uhroIRzeaDJzHfdxVpHs0oInWHkbvcCm0gxB87VPrBdqL1xUZ470pRo3Y +ekRVItloOTRS7mJ7VruGK1qSE3I3WnSxxjKbjKA1qE6tNDTEBGGdaLKQDw7TVOcJ23F yakw== X-Forwarded-Encrypted: i=1; AFNElJ96kLKqrdYm7pIy/ZcG/hINkrJ6IiCSg4yX8NbZ1I/S0ux6gvw30PifMvj4l33Q5nzLaZUDVC2VX5/K+EE=@vger.kernel.org X-Gm-Message-State: AOJu0Yyau8Yos2ZNBdzsU2TqJl0vIKj2oZu73VbzI0azZ2YCPXJu44gj R/t3cFWsSJzIMsK17DoYOtby43ggOI8MFqrQIYVGZrWu/Ej/T6RbyWr7bDy8qYTAbkNRuuYf54V f3XMqdjpFPuHBy+mShYO15GB1bIAcyOCg3+FokJJZA6tgc7s7QvQxO0B2gTOUS7dxdg== X-Gm-Gg: AfdE7cl5Z61SUiUM0mxu0EVUKMCEVrOPWRrdJOgmJHfESVzXF2szq1uPto0hTK/Z8wf YNq4rUXWEg3kW8lL45ZZ+0PKcQ6e2UbOCncdBgdYoGXWM1UaSmP3QT+pJsd+MsWwF9z7lY5lkiS LxQvL+xMnCtgbvvoyK0zsfK6wnQUnjhdd8+X/JbB7ih6Sk+Ne73UyuDITr4Bghx50DdCYkYr3iE mjpwRvw5x5nzXWEQptWL7x4PW2a8+l0mjBqRsLNP/tz9tGMS5M7qYOU2pk3ONgejtZyW8d/Xav4 oRU48MfipgNrm7aNCQWmRxkVJyzDyklSXkvbe3bBqjJWuO+Q+A8BJ3UzAkd86EtwI6u/PGIqLf1 EDKxnRKsFNT0bs2T9p3/SZb+uq31SicUbD6E3L2KilYbbMnHx1qtpSe7QmGgM+6LDPXCRpAYOsn QBzxCsRoNDfw== X-Received: by 2002:a05:600c:34c1:b0:493:a61a:a3bb with SMTP id 5b1f17b1804b1-493a61aa533mr85901625e9.22.1782738898526; Mon, 29 Jun 2026 06:14:58 -0700 (PDT) X-Received: by 2002:a05:600c:34c1:b0:493:a61a:a3bb with SMTP id 5b1f17b1804b1-493a61aa533mr85901235e9.22.1782738898043; Mon, 29 Jun 2026 06:14:58 -0700 (PDT) Received: from ?IPV6:2a0d:3344:5521:6b10:2eb7:f61a:75:4534? ([2a0d:3344:5521:6b10:2eb7:f61a:75:4534]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4926c278ab2sm182095195e9.1.2026.06.29.06.14.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 29 Jun 2026 06:14:57 -0700 (PDT) Message-ID: <2edcb1cd-f2db-4d0c-a0e3-fd2b4dd820fe@redhat.com> Date: Mon, 29 Jun 2026 15:14:55 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mptcp: only honor zero-length DATA_FIN when a mapping is present To: Michael Bommarito Cc: Matthieu Baerts , Mat Martineau , Geliang Tang , Eric Dumazet , Jakub Kicinski , mptcp@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260617215725.1116295-1-michael.bommarito@gmail.com> <3ad5bba8-18b9-48a6-94e0-99d958f23984@redhat.com> From: Paolo Abeni Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 6/29/26 1:00 PM, Michael Bommarito wrote: > On Mon, Jun 29, 2026 at 5:50 AM Paolo Abeni wrote: >> Isn't this fixed by commit 5e939544f9d2 ("mptcp: fix uninit-value in >> mptcp_established_options") ? > > I did the reproduction ~10 days ago on linus's latest, so definitely > still reproducing. I think 5e939544f9d2 was on the TX side and this > is about the RX option path, so they don't overlap on flows either. Right. AFAICS the RFC is a little vague about enforcing meaningful flags combination. I think it would be better to avoid another conditional while processing incoming ack. Does the following solve the issue? Thanks! --- diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 0ca60314d667..b924209a9b74 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -157,7 +157,6 @@ static void mptcp_parse_option(const struct sk_buff *skb, ptr++; flags = (*ptr++) & MPTCP_DSS_FLAG_MASK; - mp_opt->data_fin = (flags & MPTCP_DSS_DATA_FIN) != 0; mp_opt->dsn64 = (flags & MPTCP_DSS_DSN64) != 0; mp_opt->use_map = (flags & MPTCP_DSS_HAS_MAP) != 0; mp_opt->ack64 = (flags & MPTCP_DSS_ACK64) != 0; @@ -178,6 +177,7 @@ static void mptcp_parse_option(const struct sk_buff *skb, } if (mp_opt->use_map) { + mp_opt->data_fin = (flags & MPTCP_DSS_DATA_FIN) != 0; if (mp_opt->dsn64) expected_opsize += TCPOLEN_MPTCP_DSS_MAP64; else