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 1869C425CEE; Tue, 16 Jun 2026 16:28:43 +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=1781627325; cv=none; b=iPJmdAuUwjv2xS5BVDrWDhu7oZVTekyy+NFUxhNg3qZKORODgyMKqMP4L/rl+/TPWn1F7WLU6w8JpFvMpzOqBFP68mV+zyaXSiFe3dtcb9MIN5mZW4Uh3A1d6bNecyfaJ2gnJBwMqbjomNViz4oZOzf7zMuLcKkC95Hp4W3dTls= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781627325; c=relaxed/simple; bh=XM2l4vO85xolr6Hq+XMNdgfFXxBYMchn8xoEl/RRuns=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hsPqFn55WZK8tGYixLf5+GEEwRAEQq3n5UDF7uSxDVxHNH1PLkwXHZsEPbFvewc5nKla4QOOYQNo4KrXBpytdNxG2QNHVbc5jD4LwN9FRnfVCybuDdCdREKDFvReI19Q30SBONJQin982a3p9kD8L2hAUtD0fzMu36869GouoYY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lFt9yiwL; 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="lFt9yiwL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D40541F000E9; Tue, 16 Jun 2026 16:28:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781627323; bh=gSlshGAov9h22XXYcjMRm8S8M3pyonFAQXZv+WzAg5c=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lFt9yiwL3aI+BzUntLQeD4iDvvZluuKlVtU9sspXv34V/lnecTd1aGMj7ILIxCWY0 I6nqQtYO9dmPvtDzq6brHnI5jVTYekzqoLnMTX5UJ/XksCzHjtQFwHTpWAV84tFSfz FQ5xD8ONIlBKAVlU8ZvF9+8pjrErpP6GQiTC/FTg= 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 6.12 156/261] mptcp: fix retransmission loop when csum is enabled Date: Tue, 16 Jun 2026 20:29:54 +0530 Message-ID: <20260616145052.308608554@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145044.869532709@linuxfoundation.org> References: <20260616145044.869532709@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 6.12-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 @@ -2810,6 +2810,10 @@ 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);