Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754914AbaKYLLD (ORCPT ); Tue, 25 Nov 2014 06:11:03 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:58856 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753719AbaKYKmm (ORCPT ); Tue, 25 Nov 2014 05:42:42 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Herbert Xu , "David S. Miller" , Luis Henriques Subject: [PATCH 3.16.y-ckt 169/254] macvtap: Fix csum_start when VLAN tags are present Date: Tue, 25 Nov 2014 10:38:39 +0000 Message-Id: <1416912004-5928-170-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1416912004-5928-1-git-send-email-luis.henriques@canonical.com> References: <1416912004-5928-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt2 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Herbert Xu commit 3ce9b20f1971690b8b3b620e735ec99431573b39 upstream. When VLAN is in use in macvtap_put_user, we end up setting csum_start to the wrong place. The result is that the whoever ends up doing the checksum setting will corrupt the packet instead of writing the checksum to the expected location, usually this means writing the checksum with an offset of -4. This patch fixes this by adjusting csum_start when VLAN tags are detected. Fixes: f09e2249c4f5 ("macvtap: restore vlan header on user read") Signed-off-by: Herbert Xu Cheers, Signed-off-by: David S. Miller Signed-off-by: Luis Henriques --- drivers/net/macvtap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index 0c6adaaf898c..ff1acf99c10b 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -626,6 +626,8 @@ static void macvtap_skb_to_vnet_hdr(const struct sk_buff *skb, if (skb->ip_summed == CHECKSUM_PARTIAL) { vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; vnet_hdr->csum_start = skb_checksum_start_offset(skb); + if (vlan_tx_tag_present(skb)) + vnet_hdr->csum_start += VLAN_HLEN; vnet_hdr->csum_offset = skb->csum_offset; } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID; -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/