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 DC7BA3D8105; Tue, 16 Jun 2026 18:23:40 +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=1781634221; cv=none; b=c0WgEUAvY1qA6w7kt0OURSIfZTJ3eCKZfj1WHhQ7PXAOMHjlyaiTtidbr+F0jOoUSn8acQid+MEZ2SxG6xtUdEglczu4asXvEGztFFePOkEpkVYmjvp2u5ljy5KfHw74XgWog+RY12OYrekczpG+iVA/a3fixNOCpi4T1UgdkZI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781634221; c=relaxed/simple; bh=ZWElGjKb7XTaarr5sGwXn3gWRt0j+42t70xVqGvTkek=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IIh1qI/+vWUruhrDjuj1u+2mfDhWNUxPbSi0IFeckcEpcMqfxW++aChEZ0fUchfkL6akg3frMl2zeLIGC6l93a4+FDNpg+pLuu8+R8x4JQOUO1CZvg81vDyZjyx+50k4I/QXM+l3j5uY8NMJ84AkbOS5ktGh9S/lbf/b2gtY/So= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CrvvdCyH; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="CrvvdCyH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E5B9D1F000E9; Tue, 16 Jun 2026 18:23:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781634220; bh=OL/7I2fQTwsFr0IZU22zyfpfFqvgSH5K/vrkY8zaF1o=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=CrvvdCyHiZX0/pDWsOuoRKiDsslU0eUXLpifd490B5gYqWWfXhwZq78Yil3xOCjMU fVy0CbA7kN6heSFlUgx7lPuyqifYE5I/HF646uIgRUstpB0WQYx/nCiHhgVK9u0ukf O50f6Ih30qkxH+eQGA32+UyOYdfcpuDC0eu2M5nw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paolo Abeni , "Matthieu Baerts (NGI0)" , Jakub Kicinski Subject: [PATCH 5.15 214/411] mptcp: fix retransmission loop when csum is enabled Date: Tue, 16 Jun 2026 20:27:32 +0530 Message-ID: <20260616145112.144612918@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145100.376842714@linuxfoundation.org> References: <20260616145100.376842714@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni commit d1918b36edcaed0ec4ef6888b2358c6b1ddcff47 upstream. Sashiko noted that retransmission with csum enabled can actually transmit new data, but currently the relevant code does not update accordingly snd_nxt. The may cause incoming ack drop and an endless retransmission loop. Address the issue incrementing snd_nxt as needed. Fixes: 4e14867d5e91 ("mptcp: tune re-injections for csum enabled mode") 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/20260602-net-mptcp-misc-fixes-7-1-rc7-v2-2-856831229976@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/mptcp/protocol.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2539,6 +2539,10 @@ static void __mptcp_retrans(struct sock release_sock(ssk); + /* With csum enabled retransmission can send new data. */ + if (after64(dfrag->already_sent + dfrag->data_seq, msk->snd_nxt)) + WRITE_ONCE(msk->snd_nxt, dfrag->already_sent + dfrag->data_seq); + reset_timer: if (!mptcp_rtx_timer_pending(sk)) mptcp_reset_rtx_timer(sk);