On Mon, 2026-01-05 at 11:46 +0100, Toke Høiland-Jørgensen wrote: > KaFai Wan <[email protected]> writes: > > > This fix reverts to the original version and ensures data_hard_start > > correctly points to the xdp_frame structure, eliminating the security > > risk. > > This is wrong. We should just be checking the meta_len on input to > account for the size of xdp_frame. I'll send a patch.
Current version the actual limit of the max input meta_len for live frames is XDP_PACKET_HEADROOM - sizeof(struct xdp_frame), not XDP_PACKET_HEADROOM. The original version not set xdp_buff->data_hard_start with xdp_frame, I set it with the correct position by adding the headroom, so there is no need for user to reduce the max input meta_len. This patch is failed with the xdp_do_redirect test, I'll fix and send v2 if you're ok with that. > > -Toke > -- Thanks, KaFai
