# Re: \[Intel-wired-lan\] \[PATCH net-next 1/2\] igc: AF\_XDP zero-copy metadata adjust breaks SKBs on XDP\_PASS

- From: Kraus, NechamaX \<hidden\>
- Date: 2021-11-21 10:32:20 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/11/7786118
- Thread: https://ratatoskr.run/netdev/2021/11/7785828/t.md

```text
On 11/15/2021 22:36, Jesper Dangaard Brouer wrote:
> Driver already implicitly supports XDP metadata access in AF_XDP
> zero-copy mode, as xsk_buff_pool's xp_alloc() naturally set xdp_buff
> data_meta equal data.
>
> This works fine for XDP and AF_XDP, but if a BPF-prog adjust via
> bpf_xdp_adjust_meta() and choose to call XDP_PASS, then igc function
> igc_construct_skb_zc() will construct an invalid SKB packet. The
> function correctly include the xdp->data_meta area in the memcpy, but
> forgot to pull header to take metasize into account.
>
> Fixes: fc9df2a0b520 ("igc: Enable RX via AF_XDP zero-copy")
> Signed-off-by: Jesper Dangaard Brouer <redacted>
> ---
>   drivers/net/ethernet/intel/igc/igc_main.c |    4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
Tested-by: Nechama Kraus <redacted>


```