Commit 4fa8fcd3 authored by Jesper Dangaard Brouer's avatar Jesper Dangaard Brouer Committed by Tony Nguyen
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igc: AF_XDP zero-copy metadata adjust breaks SKBs on XDP_PASS 



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: fc9df2a0 ("igc: Enable RX via AF_XDP zero-copy")
Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Tested-by: default avatarNechama Kraus <nechamax.kraus@linux.intel.com>
Acked-by: default avatarMaciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
parent 196073f9

drivers/net/ethernet/intel/igc/igc_main.c

+3 −1
Original line number Diff line number Diff line
@@ -2448,8 +2448,10 @@ static struct sk_buff *igc_construct_skb_zc(struct igc_ring *ring, 


	skb_reserve(skb, xdp->data_meta - xdp->data_hard_start);

	memcpy(__skb_put(skb, totalsize), xdp->data_meta, totalsize);

	if (metasize)

	if (metasize) {

		skb_metadata_set(skb, metasize);

		__skb_pull(skb, metasize);

	}



	return skb;

}