From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61BDEC433E0 for ; Thu, 2 Jul 2020 01:33:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D34B2082F for ; Thu, 2 Jul 2020 01:33:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593653633; bh=72+uB+LKQB1wmd6QaomoiOLsV95GspFvxEglGh3T3AQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1Y6BL2qnCHkjAA7HfmwMz0L9iljRjtBriDOymLQNF/o7YcOwOqSzxaSf0Kt/U0mUd bs2TjnLd6nUnZT3O8HNs+cvJ1yuyR20rn+fpbc4e1BK/HHVGTCCitfsENjPn7Xettv yPE18mwjpotW27UC4tX7gklmIe58akNt4YoF9DNo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728878AbgGBBZm (ORCPT ); Wed, 1 Jul 2020 21:25:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:56666 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728853AbgGBBZk (ORCPT ); Wed, 1 Jul 2020 21:25:40 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 1F00620B1F; Thu, 2 Jul 2020 01:25:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593653139; bh=72+uB+LKQB1wmd6QaomoiOLsV95GspFvxEglGh3T3AQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=khpkV+ab3+zoEIH3OkFoDuVZv82D6Q7BhfxG7Tpdb5FUUafE1q9vTjTQjz6fXcWOe B9QonVtdlGLDVNJ3WA16sFnJRo6qZNTfAKeuJDhi2hbBqx6zdbY+YmMxph9gYGs+7f Qfq/lHHiVlI3KYbusOwUJIB8NArk1JqEr5jsJglI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jeremy Kerr , "David S . Miller" , Sasha Levin , linux-usb@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 12/40] net: usb: ax88179_178a: fix packet alignment padding Date: Wed, 1 Jul 2020 21:23:33 -0400 Message-Id: <20200702012402.2701121-12-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200702012402.2701121-1-sashal@kernel.org> References: <20200702012402.2701121-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Jeremy Kerr [ Upstream commit e869e7a17798d85829fa7d4f9bbe1eebd4b2d3f6 ] Using a AX88179 device (0b95:1790), I see two bytes of appended data on every RX packet. For example, this 48-byte ping, using 0xff as a payload byte: 04:20:22.528472 IP 192.168.1.1 > 192.168.1.2: ICMP echo request, id 2447, seq 1, length 64 0x0000: 000a cd35 ea50 000a cd35 ea4f 0800 4500 0x0010: 0054 c116 4000 4001 f63e c0a8 0101 c0a8 0x0020: 0102 0800 b633 098f 0001 87ea cd5e 0000 0x0030: 0000 dcf2 0600 0000 0000 ffff ffff ffff 0x0040: ffff ffff ffff ffff ffff ffff ffff ffff 0x0050: ffff ffff ffff ffff ffff ffff ffff ffff 0x0060: ffff 961f Those last two bytes - 96 1f - aren't part of the original packet. In the ax88179 RX path, the usbnet rx_fixup function trims a 2-byte 'alignment pseudo header' from the start of the packet, and sets the length from a per-packet field populated by hardware. It looks like that length field *includes* the 2-byte header; the current driver assumes that it's excluded. This change trims the 2-byte alignment header after we've set the packet length, so the resulting packet length is correct. While we're moving the comment around, this also fixes the spelling of 'pseudo'. Signed-off-by: Jeremy Kerr Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/usb/ax88179_178a.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c index daa54486ab094..df2f7cc6dc03a 100644 --- a/drivers/net/usb/ax88179_178a.c +++ b/drivers/net/usb/ax88179_178a.c @@ -1387,10 +1387,10 @@ static int ax88179_rx_fixup(struct usbnet *dev, struct sk_buff *skb) } if (pkt_cnt == 0) { - /* Skip IP alignment psudo header */ - skb_pull(skb, 2); skb->len = pkt_len; - skb_set_tail_pointer(skb, pkt_len); + /* Skip IP alignment pseudo header */ + skb_pull(skb, 2); + skb_set_tail_pointer(skb, skb->len); skb->truesize = pkt_len + sizeof(struct sk_buff); ax88179_rx_checksum(skb, pkt_hdr); return 1; @@ -1399,8 +1399,9 @@ static int ax88179_rx_fixup(struct usbnet *dev, struct sk_buff *skb) ax_skb = skb_clone(skb, GFP_ATOMIC); if (ax_skb) { ax_skb->len = pkt_len; - ax_skb->data = skb->data + 2; - skb_set_tail_pointer(ax_skb, pkt_len); + /* Skip IP alignment pseudo header */ + skb_pull(ax_skb, 2); + skb_set_tail_pointer(ax_skb, ax_skb->len); ax_skb->truesize = pkt_len + sizeof(struct sk_buff); ax88179_rx_checksum(ax_skb, pkt_hdr); usbnet_skb_return(dev, ax_skb); -- 2.25.1