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 6A51C233149 for ; Tue, 25 Aug 2026 16:49:18 +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=1787676559; cv=none; b=qyy8VAW1ywbOcFE4avgOswi6/gfQOUfnX9mP5buYNZx0JNSgFiSMfiuMa8Se0mq3m+A+6jfj8uYkvYfqrIvGj4QWOY4MshLC5xFBO3F6/Q5sYrdzuBkAphuOEWo67f0AQARUT8nUTf3o/ki147RVdD+r5m3v1iHf4ZaJuJJ/M5s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787676559; c=relaxed/simple; bh=Va3e+fJdkTDqgFoFG8UTmCcsZw/QWymyNXzG4sapSaI=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=sJZzPGBReuGZzMFS1kkW+wxCPRDg7I7CtM3aiYHVdy4h/J3gX4GMRz5YWkJjOSrqgkcreQYDaAngqj9YQXXBW6LPAMrKMBMlNUmOD6sNsQsA9U8ICRMIK55PZspZdg968YERG8xNYojM6cqumx9mrOzF60J6i3zSitBT5BcOCrA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CL6Z0Wq4; 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="CL6Z0Wq4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA5621F000E9; Tue, 25 Aug 2026 16:49:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787676558; bh=6MNq42QPWoExX5BKUcdGPDuEqu279O8ZgZah928MVCk=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=CL6Z0Wq4rIszUimTJ5TVORkXAKfF5gTOp1S/Ji+39FJmXK8AIDhC1hsrqTOHOF4L9 GOapkkQTC86B27Qjg5EranB3EBIGS2cKtv0tY9ufpYi1c/RmfIwP/BlbFDCyxwiNns g86PztNaXG37y1/g0MjabluOiA8geOp/5ElgkUeIx0gte8n+TDjgSJP6v2ghCm3RNl CNGvfnqGA/+9gEVbf44JZJi3OksViRs5QXpBpn/dX2NjWmGUL02PJT/aXoN93HYOym o3/SiSxrh+VEnEhsAy3Uaol2SGre9gz1ydAIChA/mIy4EP2Xhq5vci/LyrsqXdfW45 OQuxrNwXTCyNQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH net 01/14] mptcp: do not reschedule the RTX timer for fallback sockets Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?TWF0dGhpZXUgQmFlcnRzIChOR0kwKQ==?= Cc: mptcp@lists.linux.dev In-Reply-To: <20260824-net-mptcp-misc-fixes-7-3-rc1-v1-1-a92309d121ca@kernel.org> References: <20260824-net-mptcp-misc-fixes-7-3-rc1-v1-0-a92309d121ca@kernel.org> <20260824-net-mptcp-misc-fixes-7-3-rc1-v1-1-a92309d121ca@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 25 Aug 2026 16:49:17 +0000 Message-Id: <20260825164917.EA5621F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: - [High] MPTCP_RTX_DISABLED is set on TCP_CLOSE but never cleared if a conn= ection fails synchronously, permanently disabling retransmissions if the so= cket is retried. -- --- Patch [1]: [PATCH net 01/14] mptcp: do not reschedule the RTX timer for= fallback sockets --- commit e15c87662e83ee7836d581b8ebc2d5e99a964d98 Author: Paolo Abeni mptcp: do not reschedule the RTX timer for fallback sockets This commit stops the MPTCP core from rescheduling the retransmission timer for fallback sockets. It uses a new flag bit MPTCP_RTX_DISABLED to prevent rescheduling during fallback and when transitioning to TCP_CLOSE. > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > index b474d03620a75..23dde0b7144bb 100644 > --- a/net/mptcp/protocol.c > +++ b/net/mptcp/protocol.c [ ... ] > @@ -3324,6 +3326,9 @@ void mptcp_set_state(struct sock *sk, int state) > * transition from TCP_SYN_RECV to TCP_CLOSE_WAIT. > */ > break; > + case TCP_CLOSE: > + set_bit(MPTCP_RTX_DISABLED, &mptcp_sk(sk)->flags); > + fallthrough; [Severity: High] Does this permanently disable retransmissions if a socket is reused after a failed connect? If an application calls connect() and it fails synchronously (for example, connection refused), mptcp_connect() handles the error by calling mptcp_set_state(sk, TCP_CLOSE). This sets the MPTCP_RTX_DISABLED flag. If the application then retries connect() on the same socket, mptcp_connect= () transitions the socket to TCP_SYN_SENT but never clears the sticky MPTCP_RTX_DISABLED flag. Because the flag remains set, mptcp_reset_rtx_timer() will permanently abort arming the retransmission timer for this socket, which could cause the reused connection to hang indefinitely upon packet loss. > default: > if (oldstate =3D=3D TCP_ESTABLISHED || oldstate =3D=3D TCP_CLOSE_WAIT) > MPTCP_DEC_STATS(sock_net(sk), MPTCP_MIB_CURRESTAB); --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260824-net-mptcp-= misc-fixes-7-3-rc1-v1-0-a92309d121ca@kernel.org?part=3D1