From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 0C48E37CD20 for ; Mon, 6 Jul 2026 15:07:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783350469; cv=none; b=IgOmVX/gVVz2Swdz61ZrkUEFWShdzdZlFSf77imQF03xdgRTI9KMt5KdMuifRiAxtoTc5LFbYl1OZGLzzvzFH/w/i/bID45C5y2KjfAsTA3wCLPvLkWSftyrg3jfdkWaj+Ub6cCBX91x1ZsxD0slMIfbzuXbuXIInXJkqJTDET0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783350469; c=relaxed/simple; bh=dagzFoxf2pMZVfGjGf0T46LtGX3Rtygp8nZpz3V1zQQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=l1ZQGEq3aJENr8DeDq8dZJzojCc5Mcj//0AW4yi+Ee8enaguUP5ysDjt3iA6f6OzsQY37OHN1XUbii9tgzZb/L7KReZjSk8jtMgsYe3J/ra55Qb4WDSdZAXglfIL4ky9o6Q7l5/7t7ATnP5oCEtTBHV6m1OXYBePYelpbFLJrdQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Kk/uXFCO; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Kk/uXFCO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE0A41F000E9; Mon, 6 Jul 2026 15:07:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783350467; bh=X1QgJqjjS3k0ii9I4cU9Inqo6zzrbVmibV/P46QbOuU=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=Kk/uXFCOw3WhR9Tz/gJp2Nc8NyE9xcfMZADgfPEHtk+v227QS81J9lY8VYfv/zN/F stwC9fxVe1U3K3/vaEZShYlfHqqOnvJleO6KpP2lvZcgg5Z8wbuGen8ubvM919bUzL WkByuEn4EelP8RLyLcQXZJN5OOo7uYnG1gfrwHjBKPreWxkXbjS+faOm5BeGDr6GGu CPa8XkPeyApiZJ0YrHQRvXKtgpd9umjmnnlk2eHYc82jxAbUlPuyxGFQkAdcr3ibPm FwL/X/ZZX5Kxab5cIqbT5bhzfwlGcL+l7WxKnyOWX0kQGz2jY9yqWXOP78ohsOJLj/ UZZuMd3N7mAWA== Message-ID: <775e5b9e-2f00-4316-a5a2-5a333c44ae20@kernel.org> Date: Mon, 6 Jul 2026 17:07:44 +0200 Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH mptcp-net v2] mptcp: fix extra_subflows leak on failed passive join Content-Language: fr To: Geliang Tang , Chenguang Zhao , mptcp@lists.linux.dev Cc: Chenguang Zhao References: <20260630095432.1340629-1-chenguang.zhao@linux.dev> <20260701032011.358940-1-chenguang.zhao@linux.dev> <86e9b7f9ac5d630a0bb7b127652544176921a491.camel@kernel.org> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Geliang, Chenguang, On 01/07/2026 08:32, Geliang Tang wrote: > Hi Chenguang, > > Thanks for this v2. However, if there are no code changes, there is no > need to send a v2; we can just reply to the email thread on v1 to > discuss it. Indeed. Also, it is easier if you start a new thread with a link to the previous version, than replying to a previous version. > On Wed, 2026-07-01 at 11:20 +0800, Chenguang Zhao wrote: >> From: Chenguang Zhao >> >> mptcp_pm_allow_new_subflow() increments extra_subflows >> before __mptcp_finish_join() on the passive MP_JOIN path. >> On synchronous join failure the subflow is dropped without >> calling mptcp_close_ssk(), so the counter is not rolled back. What do you mean by saying "On synchronous join failure"? When I look at the packetdrill test, we are not talking about synchronous MP_JOIN (SYN + MP_JOIN packets in both directions), right? >> Call mptcp_pm_close_subflow() when the join completion fails. >> >> Fixes: 3e5014909b56 ("mptcp: cleanup MPJ subflow list handling") >> Signed-off-by: Chenguang Zhao >> Reviewed-by: Matthieu Baerts (NGI0) >> --- >> v2: >>  Hi Matthieu, >>  Thanks for the review. >>  - I spotted this by reading the code. I don't have a reproducer >>    yet. I also see we already have a Packetdrill test for >>    synchronous connect failure (simult_connect.pkt), but not for >>    synchronous join failure. I'll add a similar Packetdrill test >>    for that case and send it in a follow-up patch. >>  - Add Fixes and Reviewd-by tag. >>  - I looked again at the history, and I think the Fixes tag >>    should point to 3e5014909b56 ("mptcp: cleanup MPJ subflow list >>    handling"), not 10f6d46c943d ("mptcp: fix race between MP_JOIN and >> close"). > > The Fixes tag is incorrect and should be 10f6d46c943d ("mptcp: fix race > between MP_JOIN and close"), because that commit introduced the call to > mptcp_pm_allow_new_subflow. There is no need to send a v3, as this can > be updated when applying. +1 > I have changed the status of v2 to "Queued" and v1 to "Superseded". I will wait to get the packetdrill test ready before applying this patch. Cheers, Matt -- Sponsored by the NGI0 Core fund.