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 236CC19F13F for ; Tue, 29 Jul 2025 21:03:09 +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=1753822990; cv=none; b=slNIlep7kOtzuSkF/S97QSg6U8/ds1ygI6lERW6ktAyKzci1diiZRheXSeVvk9wwxCPC7kEWkZa0X4G84sqJafP9k+vcFtGcNL/W6Nt9egYEZ7/P/yrHFWQ6gBf2sG5cw8Dse0bWEUbmJd98c/mRPBATxJ6AGXt8JX4jRVbjPuE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753822990; c=relaxed/simple; bh=4K/4f1DZTkQ74ebU/eKzIDEW/PMj+iSRVzGofAVoJ8o=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=k2m1i6Mx/+ro9OlA/jUeKbcvupx1lWZvVH7FIqS5fwVcXn1cYuP4+F0UAnfmrJAxnXvtuph63BZHoVs3YswGkD8coqrTIN5NYOndcLPavXi3nG7EFWNtG968P4O50wwRcuN3M0yRMUlxPQXVyI4YaUbTRLUqoOelt6d/30pndvM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JG8Vqmbv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JG8Vqmbv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FEF4C4CEEF; Tue, 29 Jul 2025 21:03:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1753822989; bh=4K/4f1DZTkQ74ebU/eKzIDEW/PMj+iSRVzGofAVoJ8o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JG8Vqmbvf8ac4x55XsOO8JL5aAW/NA52DRc9OE/3ZP6AIgI2y2C4FpMKl+tfZhIpc BT8BWDdnMbQayGXeLP5w9Yb1hXqjAlOXGAZlSFWpQ1RbSZLMpsPrrVUhN8FfPMPQRs pkChFjH2qOVJK8jHUHsY161djxCyg/belukiYV/PmmTSevoMPfVswx93TGVjx0ytVh 53oRsVyElEDvNVbseEdPosT2KdANfqLrR7uqSplPTybCWbttrJ/HH6hsSGH46gRADy jDINi/XxfZlXynoNfVoGRtFtiB4se7lAherbAljePcKj/wzDXZHzaJnw5bGo0J65UC 6ZyVLSXOGU2Kg== From: Sasha Levin To: stable@vger.kernel.org Cc: Sasha Levin Subject: Re: [PATCH 6.1.y 3/3] mptcp: reset fallback status gracefully at disconnect() time Date: Tue, 29 Jul 2025 17:03:07 -0400 Message-Id: <1753816740-791ed0de@stable.kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250728132919.3904847-8-matttbe@kernel.org> References: Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Sasha's backport helper bot ] Hi, ✅ All tests passed successfully. No issues detected. No action required from the submitter. The upstream commit SHA1 provided is correct: da9b2fc7b73d147d88abe1922de5ab72d72d7756 WARNING: Author mismatch between patch and upstream commit: Backport author: Matthieu Baerts (NGI0) Commit author: Paolo Abeni Status in newer kernel trees: 6.15.y | Not found 6.12.y | Not found 6.6.y | Not found Note: The patch differs from the upstream commit: --- 1: da9b2fc7b73d ! 1: 96832530025f mptcp: reset fallback status gracefully at disconnect() time @@ Metadata ## Commit message ## mptcp: reset fallback status gracefully at disconnect() time + commit da9b2fc7b73d147d88abe1922de5ab72d72d7756 upstream. + mptcp_disconnect() clears the fallback bit unconditionally, without touching the associated flags. @@ Commit message Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250714-net-mptcp-fallback-races-v1-3-391aff963322@kernel.org Signed-off-by: Jakub Kicinski + [ Conflicts in protocol.c, because commit ebc1e08f01eb ("mptcp: drop + last_snd and MPTCP_RESET_SCHEDULER") is not in this version and + changed the context. The same modification can still be applied at the + same place. ] + Signed-off-by: Matthieu Baerts (NGI0) ## net/mptcp/protocol.c ## @@ net/mptcp/protocol.c: static int mptcp_disconnect(struct sock *sk, int flags) - * subflow */ mptcp_destroy_common(msk, MPTCP_CF_FASTCLOSE); + msk->last_snd = NULL; + + /* The first subflow is already in TCP_CLOSE status, the following + * can't overlap with a fallback anymore @@ net/mptcp/protocol.c: static int mptcp_disconnect(struct sock *sk, int flags) + msk->cb_flags = 0; msk->recovery = false; - WRITE_ONCE(msk->can_ack, false); + msk->can_ack = false; --- Results of testing on various branches: | Branch | Patch Apply | Build Test | |---------------------------|-------------|------------| | 6.1 | Success | Success |