From nobody Thu Nov 27 15:30:11 2025 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 D29CE1E5B64; Wed, 30 Jul 2025 09:13:29 +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=1753866809; cv=none; b=P790SKxa4k/ROAwoSNHWDVxFYZdzOHZ8EmgjWnI6ghTBow9qkToyqCbyT0BWYCejbuBFAzFh62OJ2ZM4E+Rg7lI+6Xl+InHLDxx+22gbYCzIzM7W61FttRGXnr09swGMWoAj8cVOEWo+cxHE42CQqtgIdyYm3i2JQMoP5K6IJoU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753866809; c=relaxed/simple; bh=RTerptDMBrbs3uXMAzF/CtryWEIRu+xDVS0fwWFc9Sg=; h=Subject:To:Cc:From:Date:In-Reply-To:Message-ID:MIME-Version: Content-Type; b=p9mO3aFPVieFEgtAFgymPyJ+Wk4kzVLj2ZY2ype7kKP2n7N0KLKoMp2e85oMURWmUVsqny8Hk9AtKiW0fylYK1/FU/zckSwFIcsHJjJYLeVvpPVd/wXMditoLcYMNU1ZvzpC+4boVakFMwRBsAYAROIy5lWSB8TvAYdBpejxmF4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VZQCPNaf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="VZQCPNaf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4AAF3C4CEF5; Wed, 30 Jul 2025 09:13:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1753866809; bh=RTerptDMBrbs3uXMAzF/CtryWEIRu+xDVS0fwWFc9Sg=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=VZQCPNaf/Lj4K2SpEeyvRWiAo5ceW8UKHn5T+1sLKpF8L/+56w2JEuTo2mdJlipjS 0Ueeus5pVf8yR843hlw947qAYMIvtbv5EEOmwlUBKrEghcolJ1C5FTwpo9Sj0PSflU Ydu047Zj67fE+FquMCq4TqSSssCDRkNDS9qs1j+0= Subject: Patch "mptcp: reset fallback status gracefully at disconnect() time" has been added to the 6.6-stable tree To: gregkh@linuxfoundation.org,kuba@kernel.org,matttbe@kernel.org,mptcp@lists.linux.dev,pabeni@redhat.com,sashal@kernel.org Cc: From: Date: Wed, 30 Jul 2025 11:13:04 +0200 In-Reply-To: <20250728091448.3494479-8-matttbe@kernel.org> Message-ID: <2025073004-ferocity-uplifting-2364@gregkh> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-stable: commit X-Patchwork-Hint: ignore Content-Type: text/plain; charset="utf-8" This is a note to let you know that I've just added the patch titled mptcp: reset fallback status gracefully at disconnect() time to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=3Dlinux/kernel/git/stable/stable-queue.git= ;a=3Dsummary The filename of the patch is: mptcp-reset-fallback-status-gracefully-at-disconnect-time.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. From stable+bounces-164898-greg=3Dkroah.com@vger.kernel.org Mon Jul 28 11:1= 5:34 2025 From: "Matthieu Baerts (NGI0)" Date: Mon, 28 Jul 2025 11:14:51 +0200 Subject: mptcp: reset fallback status gracefully at disconnect() time To: mptcp@lists.linux.dev, stable@vger.kernel.org, gregkh@linuxfoundation.o= rg Cc: Paolo Abeni , sashal@kernel.org, "Matthieu Baerts (N= GI0)" , Jakub Kicinski Message-ID: <20250728091448.3494479-8-matttbe@kernel.org> From: Paolo Abeni commit da9b2fc7b73d147d88abe1922de5ab72d72d7756 upstream. mptcp_disconnect() clears the fallback bit unconditionally, without touching the associated flags. The bit clear is safe, as no fallback operation can race with that -- all subflow are already in TCP_CLOSE status thanks to the previous FASTCLOSE -- but we need to consistently reset all the fallback related status. Also acquire the relevant lock, to avoid fouling static analyzers. Fixes: b29fcfb54cd7 ("mptcp: full disconnect implementation") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250714-net-mptcp-fallback-races-v1-3-391af= f963322@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Matthieu Baerts (NGI0) Signed-off-by: Greg Kroah-Hartman --- net/mptcp/protocol.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3208,7 +3208,16 @@ static int mptcp_disconnect(struct sock * subflow */ mptcp_destroy_common(msk, MPTCP_CF_FASTCLOSE); + + /* The first subflow is already in TCP_CLOSE status, the following + * can't overlap with a fallback anymore + */ + spin_lock_bh(&msk->fallback_lock); + msk->allow_subflows =3D true; + msk->allow_infinite_fallback =3D true; WRITE_ONCE(msk->flags, 0); + spin_unlock_bh(&msk->fallback_lock); + msk->cb_flags =3D 0; msk->recovery =3D false; msk->can_ack =3D false; Patches currently in stable-queue which might be from matttbe@kernel.org are queue-6.6/selftests-mptcp-connect-also-cover-alt-modes.patch queue-6.6/selftests-mptcp-connect-also-cover-checksum.patch queue-6.6/mptcp-plug-races-between-subflow-fail-and-subflow-creation.patch queue-6.6/mptcp-make-fallback-action-and-fallback-decision-atomic.patch queue-6.6/mptcp-reset-fallback-status-gracefully-at-disconnect-time.patch