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 422225477E; Sun, 16 Aug 2026 17:31:52 +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=1786901513; cv=none; b=I2NIZEKD8W1HhTHcjhne18jD1w/jrOsmxGn6MOqumek1sRRfVupaNuoKY2W7dyOoDV5qKd+Hx9j0HnSQ5MAKifBaO+7lTJ4Iqfu3lcAwjQNlmDTyzUB6VXNp7XLuTDi4V1TmGeSsxN1NwgZfXXalb4yQarg7FTTjX+3W322WPXg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786901513; c=relaxed/simple; bh=eA8hUazT8uGAbzaAi6BpxlBElQzOCp7R32DPn7wL8LI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=OzN2JJrgNWYChgkUGp1zOJm9/juWutj0E0Btnu8h4OOlNdPfTQY/K7PSs/uT4D3x0esHudnCl0dcJv1fY7ClI5QN+3olMgYROx21srk/QKGVWVDvk60wjIWBlbp0fRZBM5uur92QHPwp/i7mbtQMdFXVBBAdQLQOgH9eHC8EPz0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VWDSdQe2; 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="VWDSdQe2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A5571F000E9; Sun, 16 Aug 2026 17:31:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786901511; bh=UQ71jAqB89Ibnvdbmp5P0Np0dgcwLAJ/2WfpvOGlF7c=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=VWDSdQe2JRIo3PtGZzPQaBrXVaZ3FDuPZNDJEd2V5xxEroB35xn1IfPIv9ORludSc 2AQBwA+LRPtiKeXIOnR6HQlyVyQdxp0al/BK/OeVcexzC7N3D5rm/zB9+dADKNDRWc NO1SSTxkY+vvwU4NG6xRYt96/ySLPlq36lB75tQ5sZ78EGm9mwLCIusIlk3yjK0xGr EHmfgvZOqndzLAMDIm6JF3iSdMn5xUl4+RcQbkRuZWeu/uvSeVjfngJxZU5gGocSCC UYE2asRAjm1wJoYwf5NyuuntWAzLdOaCFl/kvdUuMUVLrWux0rDfVDmT7xVE1yeiq5 Hc2YQzKSYrD9Q== Message-ID: <4e9b815b-d116-4a34-b88d-297f3270d7f3@kernel.org> Date: Sun, 16 Aug 2026 19:31:47 +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 net] mptcp: fix uninitialized local_id in syncookie MP_JOIN reconstruction Content-Language: fr To: Harshit Varu , netdev@vger.kernel.org Cc: mptcp@lists.linux.dev, martineau@kernel.org, geliang@kernel.org, stable@vger.kernel.org References: <20260815115205.197151-1-harshitvaru666@gmail.com> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Harshit, On 15/08/2026 13:52, Harshit Varu wrote: > mptcp_token_join_cookie_init_state() restores remote_nonce, local_nonce, > backup, join_id, token and msk from the saved cookie entry when rebuilding > the request socket for a MP_JOIN 4th-ACK handled under SYN cookies, but it > does not restore local_id, even though the SYN path saved it. > subflow_ulp_clone() then reads that uninitialized field and stores it as > the joined subflow's address-ID. Because the request-sock slab is > SLAB_TYPESAFE_BY_RCU and not zeroed on allocation, the value is the stale > byte of a previously freed request socket, which an off-path peer can > influence by sending concurrent MP_JOIN SYNs. This corrupts the path > manager's id-based subflow bookkeeping for the connection. Thank you for this new version: Reviewed-by: Matthieu Baerts (NGI0) Please next time add all the reviewers in cc -- as requested in your v2 -- and add the version number in the prefix. No need to send a new version to address that. Cheers, Matt -- Sponsored by the NGI0 Core fund.