From afd5ba577c10639f62e8120df67dc70ea4b61176 Mon Sep 17 00:00:00 2001 From: Amery Hung Date: Thu, 16 Oct 2025 22:55:39 +0300 Subject: [PATCH] net/mlx5e: RX, Fix generating skb from non-linear xdp_buff for legacy RQ XDP programs can release xdp_buff fragments when calling bpf_xdp_adjust_tail(). The driver currently assumes the number of fragments to be unchanged and may generate skb with wrong truesize or containing invalid frags. Fix the bug by generating skb according to xdp_buff after the XDP program runs. Fixes: ea5d49bdae8b ("net/mlx5e: Add XDP multi buffer support to the non-linear legacy RQ") Reviewed-by: Dragos Tatulea Signed-off-by: Amery Hung Signed-off-by: Tariq Toukan Link: https://patch.msgid.link/1760644540-899148-2-git-send-email-tariqt@nvidia.com Signed-off-by: Jakub Kicinski --- .../net/ethernet/mellanox/mlx5/core/en_rx.c | 25 ++++++++++++++----- 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c index 263d5628ee44e..17cab14b328b9 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c @@ -1794,14 +1794,27 @@ mlx5e_skb_from_cqe_nonlinear(struct mlx5e_rq *rq, struct mlx5e_wqe_frag_info *wi } prog = rcu_dereference(rq->xdp_prog); - if (prog && mlx5e_xdp_handle(rq, prog, mxbuf)) { - if (__test_and_clear_bit(MLX5E_RQ_FLAG_XDP_XMIT, rq->flags)) { - struct mlx5e_wqe_frag_info *pwi; + if (prog) { + u8 nr_frags_free, old_nr_frags = sinfo->nr_frags; + + if (mlx5e_xdp_handle(rq, prog, mxbuf)) { + if (__test_and_clear_bit(MLX5E_RQ_FLAG_XDP_XMIT, + rq->flags)) { + struct mlx5e_wqe_frag_info *pwi; + + wi -= old_nr_frags - sinfo->nr_frags; + + for (pwi = head_wi; pwi < wi; pwi++) + pwi->frag_page->frags++; + } + return NULL; /* page/packet was consumed by XDP */ + } - for (pwi = head_wi; pwi < wi; pwi++) - pwi->frag_page->frags++; + nr_frags_free = old_nr_frags - sinfo->nr_frags; + if (unlikely(nr_frags_free)) { + wi -= nr_frags_free; + truesize -= nr_frags_free * frag_info->frag_stride; } - return NULL; /* page/packet was consumed by XDP */ } skb = mlx5e_build_linear_skb( -- 2.47.3