Re: [PATCH net-next v2 03/10] net/mlx5e: check for failure when pulling the Ethernet header after XDP
flat view
From: Tariq Toukan <tariqt@nvidia.com>
Date: 2026-10-13 10:02:41
Also in:
intel-wired-lan, linux-rdma, lkml, xen-devel
On 09/10/2026 0:02, Josef Bacik wrote:
When an XDP program leaves less than ETH_HLEN in the linear part of a multi-buffer packet, mlx5e_skb_from_cqe_mpwrq_nonlinear() pulls the rest of the Ethernet header in from the frags with __pskb_pull_tail() and ignores the return value. If that pull fails, eth_type_trans() later finds less than ETH_HLEN in the head and BUG()s in __skb_pull(). Use pskb_may_pull() instead and drop the packet if it fails. Pulling min(ETH_HLEN, skb->len) keeps today's behaviour for a frame shorter than an Ethernet header. Assisted-by: LLM Signed-off-by: Josef Bacik <josef@toxicpanda.com> --- drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
Hi, I posted relevant comments on V1. https://lore.kernel.org/all/d2d64d12-24a9-4bf1-b505-3008e0e25c40@nvidia.com/ (local)
quoted hunk ↗ jump to hunk
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c index e3f915beebe1..b1e1e30a77e2 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c@@ -2060,9 +2060,12 @@ mlx5e_skb_from_cqe_mpwrq_nonlinear(struct mlx5e_rq *rq, struct mlx5e_mpw_info *w pagep->frags++; while (++pagep < frag_page); - if (len < ETH_HLEN) - __pskb_pull_tail(skb, min(ETH_HLEN - len, - skb->data_len)); + if (len < ETH_HLEN && + !pskb_may_pull(skb, min(ETH_HLEN, skb->len))) { + rq->stats->buff_alloc_err++; + dev_kfree_skb_any(skb); + return NULL; + } } } else { if (xdp_buff_has_frags(&mxbuf->xdp)) {