From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-4323.protonmail.ch (mail-4323.protonmail.ch [185.70.43.23]) (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 D0C1B33E36A; Tue, 25 Aug 2026 23:55:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.70.43.23 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787702158; cv=none; b=YGNU4U61+XNKbnCavX2o3z9NYhZ42JK4uja0kMYrhBGJHNdPCAwnOjDTHx4rWTtSxV8ApYpXeCdb51+WYw0PoeEX0BW7/ZbfDkr7prwL3VvBgEFUGGCulmvhhkJrqjweBAp35vZXKZaAHHs585lskbxD2g9OHr2uEBZK6JADWMw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787702158; c=relaxed/simple; bh=u4RhN4rbo6U/CaIYZY+2wB4CsC8y/ZHMm49Y4elRzyo=; h=Date:To:From:Cc:Subject:Message-ID:MIME-Version:Content-Type; b=pY0MMpRqBdEP/ubry29r83ollwIE94jb03Rl2Q728I9DHBtajwcvCKZqLSTWdJhfVuu0lEA3v7l+RAZkbXRHQYe4vsP8j2eqx67H4oQhcNCz5f6xbyuQBrwFeJ4OwdgVTZKBxY9UhpaQ1OANMZLGDM0JeOy3ToEaLsd6Xfxw55w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=1g4.org; spf=pass smtp.mailfrom=1g4.org; dkim=pass (2048-bit key) header.d=1g4.org header.i=@1g4.org header.b=mrGmclxG; arc=none smtp.client-ip=185.70.43.23 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=1g4.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=1g4.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=1g4.org header.i=@1g4.org header.b="mrGmclxG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1g4.org; s=protonmail3; t=1787702146; x=1787961346; bh=0zuxoKD2M1JEVqHANBIUbWduPp/SxtJyTy5Prh/oD7w=; h=Date:To:From:Cc:Subject:Message-ID:Feedback-ID:From:To:Cc:Date: Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector; b=mrGmclxGRKil5ZV/uCVKYMkGgZX257YTVHByLpKbQjafzcklEip4jwpOOgdPl2hch tqTZFnukn1bui8ETwIF6tdrefF4GR4SCv3s3aBBHDPKS8lkdI56C1nkKpaPZ1+rvPT CQGTwcanShKSG2PUZlDhKTqcAqL1mMdagjK3HMkrHwky3dHFfHFgYBtnT+gRAvkBJF dCOhDtafvMec+qinDtVQKzeH/DIUpxqP2DWiNsxQorhPCNzMyLJI+/RDr2j6vwYm7X aYVsXeF0IwZKinWiNHh08MmMxEQTonwL9f4BXX6sxUCoKuJzwnXSNQVNXV5j48aaZi FRr9h/9BRK6Zg== Date: Tue, 25 Aug 2026 23:55:40 +0000 To: intel-wired-lan@lists.osuosl.org From: Paul Moses Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, anthony.l.nguyen@intel.com, przemyslaw.kitszel@intel.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, maciej.fijalkowski@intel.com, andre.guedes@intel.com, vedang.patel@intel.com, jithu.joseph@intel.com, richardcochran@gmail.com, tkusters@aweta.nl, stable@vger.kernel.org Subject: [PATCH net] igc: only strip RX timestamp header from first buffer Message-ID: <20260825235530.3278670-1-p@1g4.org> Feedback-ID: 8253658:user:proton X-Pm-Message-ID: 8f3ba88960520ef0ca5839f4ffd264c7e10e4b08 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable igc_clean_rx_irq() strips IGC_TS_HDR_LEN whenever a descriptor reports IGC_RXDADV_STAT_TSIP. For multi-buffer packets, continuation descriptors retain TSIP even though the inline timestamp is present only in the first RX buffer. Subtracting the header length from each continuation buffer truncates jumbo packets by 16 bytes per continuation and leaves the packet length larger than the received data. Only consume the timestamp header when skb is NULL, which identifies the first buffer of a new packet. An skb carried in rx_ring->skb remains non-NULL when packet assembly resumes in a later NAPI poll. Link: https://lore.kernel.org/all/20260625-igb-rx-ts-fix-v3-1-99b3efa08dca@= aweta.nl/ Fixes: e1ed4f92a625 ("igc: Refactor Rx timestamp handling") Cc: stable@vger.kernel.org Signed-off-by: Paul Moses --- # # REPRO #=20 # Receiver: igc / enp1s0 / 10.0.5.175 # Sender: RTL8125B / enP4p65s0 / 10.0.5.165 # Both hosts sudo ip link set dev enp1s0 mtu 9000 sudo ip link set dev enP4p65s0 mtu 9000 # Baseline: RX timestamping off sudo hwstamp_ctl -i enp1s0 -t 0 -r 0 ping -n -M do -c 5 -s 8972 10.0.5.175 # 5/5 received # Enable RX timestamping only sudo hwstamp_ctl -i enp1s0 -t 0 -r 1 # Receiver sudo timeout 20 tcpdump -ni enp1s0 -s 0 -w /tmp/igc-jumbo.pcap \ 'icmp and host 10.0.5.165' # Sender ping -n -M do -c 5 -W 2 -s 8972 10.0.5.175 # 0/5 received # Receiver sudo tcpdump -nn -e -vvv -r /tmp/igc-jumbo.pcap # length 8950 # [total length 9000 > length 8936] (invalid) # wrong icmp cksum # Expected Ethernet length: 9014 # Captured length: 8950 # Loss: 64 =3D 4 continuation buffers * 16 bytes # Disable RX timestamping again sudo hwstamp_ctl -i enp1s0 -t 0 -r 0 ping -n -M do -c 5 -s 8972 10.0.5.175 # 5/5 received --- drivers/net/ethernet/intel/igc/igc_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethern= et/intel/igc/igc_main.c index 1fb5f3cbe93c..41b293dc10c3 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -2639,7 +2639,8 @@ static int igc_clean_rx_irq(struct igc_q_vector *q_ve= ctor, const int budget) =20 =09=09pktbuf =3D page_address(rx_buffer->page) + rx_buffer->page_offset; =20 -=09=09if (igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP)) { +=09=09if (!skb && +=09=09 igc_test_staterr(rx_desc, IGC_RXDADV_STAT_TSIP)) { =09=09=09ctx.rx_ts =3D pktbuf; =09=09=09pkt_offset =3D IGC_TS_HDR_LEN; =09=09=09size -=3D IGC_TS_HDR_LEN; --=20 2.55.GIT