[Intel-wired-lan] [PATCH net-next 1/2] igc: AF_XDP zero-copy metadata adjust breaks SKBs on XDP_PASS

[Jesper Dangaard Brouer]

On 26/11/2021 16.25, Maciej Fijalkowski wrote:
> On Mon, Nov 15, 2021 at 09:36:25PM +0100, 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<brouer at redhat.com>
> Acked-by: Maciej Fijalkowski<maciej.fijalkowski at intel.com>
> 
> Great catch. Will take a look at other ZC enabled Intel drivers if they
> are affected as well.

Thanks a lot for taking this task!!! :-)
--Jesper