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 8E9B443E4A1; Tue, 16 Jun 2026 15:34:16 +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=1781624057; cv=none; b=L91iNsSxMkKPinEH8ABUTjsJV1o50zWUjhttBqFhudiRsg2xEoz+eCPBPtYv2SEtS0EXOMw8yZCT5jOrZ93pvAHOEvsS+17h6BvNzTMfw1b3Ne3llDUs4AdLzOy7cqCisUqKKcMbi2dnlozWGggDVs4e9i4faudhEJO7v+EI+Ls= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781624057; c=relaxed/simple; bh=fk0nI++z9zA2W7mrXMuTSf2dYOcVyhFkN6EX/YUcAO8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dz1MaodAZgpdR+UeMc5wnMQNfoa6/+iVoUHBk7PHql+VlGxUfPcqa0oBAcfOLQKgagULKHi2Mx/S9gHJRLjuBou/Vg+FhbigU5eIB7igEJsWibAxj6aM9uMj37+ElOYg3BFyamBUn5ynTwyX+boR6nu9jX1F05ivuNoRGo1viIQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mz1VXdJ5; 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="mz1VXdJ5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E65D1F000E9; Tue, 16 Jun 2026 15:34:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781624056; bh=XBdYSq7UZNe7V4/tBuQfbQLNKSNdO1t2qJosLASfftk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=mz1VXdJ5TQEB4ykVLuou73gEVQ1ttTiwm2v7+fW6eA5GYyv0ZyyGw+UBpAf+Vf+vF fkM8js+zl7o25olSHs5pBi4iPJRRxa7bX+tvqfpZMG3kvqDH7ljDtoVk7sHhfrF6S0 Llc0wvYQot1pHguGge1yEL7T+Wn345k5K/YdShR8= 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 7.0 231/378] mptcp: fix retransmission loop when csum is enabled Date: Tue, 16 Jun 2026 20:27:42 +0530 Message-ID: <20260616145122.424610934@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145109.744539446@linuxfoundation.org> References: <20260616145109.744539446@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 7.0-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 @@ -2852,6 +2852,10 @@ 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);