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 2E4DE44BCBE; Tue, 16 Jun 2026 17:06:23 +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=1781629584; cv=none; b=bW2ON7lJVZXJOyS6WNMxPlSi0OaG5q3J9NiWwJCSDGHEeJ+zRmikaFbU8RZMbeu3YkL7KFFyoc2w80Vs/Ikx+SBAheX2t7/xlKWKD0xqddLNywxH8xi/IlnFtYlE18i0D5BWGnqSQbfBqdOxVmtepTnjVse7+p1dfTiGEMo3Erw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781629584; c=relaxed/simple; bh=foCmaRrY5v11F91IHkPIpWsMk8unBY1HkeZaUWxrrHo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=a8Ei9v99KrZsUERdZ7YvOazC0+4b8do+7qLJPrnjJHjWJx4JzF/+1Yp4rWKKOSDhLRp5bGm4TUi4xgv1LGYzUyAnWKKcKNFnFzOlJDF/MYtOHj/6NA3y3idnYUIXmxppt0T+2HXRwsH641ipmSbU3Dj0fw/HUuCdwy2JDC9cSA0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Ug49Yr+F; 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="Ug49Yr+F" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E6E91F000E9; Tue, 16 Jun 2026 17:06:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781629583; bh=SmfUr9p4fa+nlt1qO06gUGBb0xH5l2yyI8aGVWCcCr4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Ug49Yr+FxAP968ZMSB6D3dkQSFOGKCGPp2+ngivTkK1gMbuzZTC4CpCROggpQE5Sq TFoqlK6Et/BiuAWNfh1XBTVLmx95Dnfcdt+h2VmPlG/oiB73EF5CkUlzFassCE4/RA ywSDxJm7Se4dXT5hdQFRIVVqWqQ41IrkIKY6/P7k= 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 6.6 314/452] mptcp: fix retransmission loop when csum is enabled Date: Tue, 16 Jun 2026 20:29:01 +0530 Message-ID: <20260616145133.999500409@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145117.796205997@linuxfoundation.org> References: <20260616145117.796205997@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 6.6-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 @@ -2751,6 +2751,10 @@ static void __mptcp_retrans(struct sock msk->bytes_retrans += len; dfrag->already_sent = max(dfrag->already_sent, len); + /* 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: mptcp_check_and_set_pending(sk);