On Fri, Oct 6, 2017 at 3:07 AM, William Tu <u9012...@gmail.com> wrote:
> Similarly to early patch for erspan_xmit(), the ARPHDR_ETHER device
> is the length of the whole ether packet. So skb->len should subtract
> the dev->hard_header_len.
>
> Fixes: 1a66a836da63 ("gre: add collect_md mode to ERSPAN tunnel")
> Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN")
> Signed-off-by: William Tu <u9012...@gmail.com>
> Cc: Xin Long <lucien....@gmail.com>
> Cc: David Laight <david.lai...@aculab.com>
> ---
> v1->v2:
> use addition to avoid overflow
> fix pskb_trim size
> ---
> net/ipv4/ip_gre.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
> index b279c325c7f6..fb95f68d6e53 100644
> --- a/net/ipv4/ip_gre.c
> +++ b/net/ipv4/ip_gre.c
> @@ -579,8 +579,8 @@ static void erspan_fb_xmit(struct sk_buff *skb, struct
> net_device *dev,
> if (gre_handle_offloads(skb, false))
> goto err_free_rt;
>
> - if (skb->len > dev->mtu) {
> - pskb_trim(skb, dev->mtu);
> + if (skb->len > dev->mtu + dev->hard_header_len) {
> + pskb_trim(skb, dev->mtu + dev->hard_header_len);
> truncate = true;
> }
>
> @@ -731,8 +731,8 @@ static netdev_tx_t erspan_xmit(struct sk_buff *skb,
> if (skb_cow_head(skb, dev->needed_headroom))
> goto free_skb;
>
> - if (skb->len - dev->hard_header_len > dev->mtu) {
> - pskb_trim(skb, dev->mtu);
> + if (skb->len > dev->mtu + dev->hard_header_len) {
> + pskb_trim(skb, dev->mtu + dev->hard_header_len);
> truncate = true;
> }
>
> --
> 2.7.4
>
Reviewed-by: Xin Long <lucien....@gmail.com>
