From: Herbert Xu Date: Mon, 3 Nov 2014 06:01:25 +0000 (+0800) Subject: macvtap: Fix csum_start when VLAN tags are present X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=3ce9b20f1971690b8b3b620e735ec99431573b39;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git macvtap: Fix csum_start when VLAN tags are present 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") Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu Cheers, Signed-off-by: David S. Miller --- diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c index 6f226de655a4..880cc090dc44 100644 --- a/drivers/net/macvtap.c +++ b/drivers/net/macvtap.c @@ -629,6 +629,8 @@ 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;