From nobody Thu May 7 08:38:34 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 080442BFC85 for ; Wed, 29 Apr 2026 11:08:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777460920; cv=none; b=tK/pE9UEIsKqvEeXyGRxQygmyrDe4pUghgfxcVSydHUkAUaBH02Qxc5NWxvhkrx9/sjQvr5YNNqJUVrf0Ah7VpVJfhN9Sd/XjCsQQ8nExJheDoXfjJniryqXwZlEq+NxU8KGpu9if85Cswp1neksK3lxLl+ekKHlPPhccFz4r10= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777460920; c=relaxed/simple; bh=xs+DfEQS3OZqEqJZQUkiQ3u3Zhtr4bC9LsHFsv/QWO8=; h=From:To:Subject:Date:Message-ID:MIME-Version:content-type; b=IZhOyqYthxrX3z6gEnikr6skchtvCtJY1qinJvQ+uhkMXjVQPxV9xaM5FqdsL8cFG4EUiZra12I6d9GSy++t5ZtnzM+1U0i1Di1phT1tzM9A0MC/4RkSNE0NwS9OQMI8SuJcP5WmE05tx5YkWMZmZIUAYzjIERqVJNM++/9mql0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=LLREuU1C; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LLREuU1C" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1777460917; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=Z1qrjgkkirxPS5bR7WxBF06MZ+QB12CREsqv6xZvMRs=; b=LLREuU1CPP7Vp/hdBA5l9jtllNgZgzqmr7YT1dqgKgxmwx+hqiDXQGO8bvrRYU0mr27r+c /Op5ZfF8L9ac1xkex/B2O0/YQRjdLAo1F+XRCPn4RyqpKF0mlPNlpBmxK99akXIsqqwvOt WgKqQ+67Z+MtMvPTZmFvacnOxg546ro= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-80-PuT63qtMNAaCHzu0NTqEqA-1; Wed, 29 Apr 2026 07:08:36 -0400 X-MC-Unique: PuT63qtMNAaCHzu0NTqEqA-1 X-Mimecast-MFC-AGG-ID: PuT63qtMNAaCHzu0NTqEqA_1777460915 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 713A318003FC for ; Wed, 29 Apr 2026 11:08:35 +0000 (UTC) Received: from gerbillo.redhat.com (unknown [10.44.34.99]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id A11D01800480 for ; Wed, 29 Apr 2026 11:08:34 +0000 (UTC) From: Paolo Abeni To: mptcp@lists.linux.dev Subject: [PATCH mptcp-net] mptcp: fix rx timestamp corruption on fastopen Date: Wed, 29 Apr 2026 13:06:02 +0200 Message-ID: Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: GSJa48dhjbFQJtN4BIjPUufvcgDoBZivthTZthYRcsE_1777460915 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8"; x-default="true" The skb cb offset containing the timestamp presence flag is cleared before loading such information. Cache such value before MPTCP CB initialization. Fixes: 36b122baf6a8 ("mptcp: add subflow_v(4,6)_send_synack()") Signed-off-by: Paolo Abeni Reviewed-by: Matthieu Baerts (NGI0) --- net/mptcp/fastopen.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/mptcp/fastopen.c b/net/mptcp/fastopen.c index 82ec15bcfd7f..082c46c0f50e 100644 --- a/net/mptcp/fastopen.c +++ b/net/mptcp/fastopen.c @@ -12,6 +12,7 @@ void mptcp_fastopen_subflow_synack_set_params(struct mptc= p_subflow_context *subf struct sock *sk, *ssk; struct sk_buff *skb; struct tcp_sock *tp; + bool has_rxtstamp; =20 /* on early fallback the subflow context is deleted by * subflow_syn_recv_sock() @@ -40,12 +41,13 @@ void mptcp_fastopen_subflow_synack_set_params(struct mp= tcp_subflow_context *subf */ tp->copied_seq +=3D skb->len; subflow->ssn_offset +=3D skb->len; + has_rxtstamp =3D TCP_SKB_CB(skb)->has_rxtstamp; =20 /* Only the sequence delta is relevant */ MPTCP_SKB_CB(skb)->map_seq =3D -skb->len; MPTCP_SKB_CB(skb)->end_seq =3D 0; MPTCP_SKB_CB(skb)->offset =3D 0; - MPTCP_SKB_CB(skb)->has_rxtstamp =3D TCP_SKB_CB(skb)->has_rxtstamp; + MPTCP_SKB_CB(skb)->has_rxtstamp =3D has_rxtstamp; MPTCP_SKB_CB(skb)->cant_coalesce =3D 1; =20 mptcp_data_lock(sk); --=20 2.53.0