From e142dc4ef0f451b7ef99d09aaa84e9389af629d7 Mon Sep 17 00:00:00 2001 From: Larysa Zaremba Date: Thu, 5 Mar 2026 12:12:45 +0100 Subject: [PATCH] ice: change XDP RxQ frag_size from DMA write length to xdp.frame_sz The only user of frag_size field in XDP RxQ info is bpf_xdp_frags_increase_tail(). It clearly expects whole buff size instead of DMA write size. Different assumptions in ice driver configuration lead to negative tailroom. This allows to trigger kernel panic, when using XDP_ADJUST_TAIL_GROW_MULTI_BUFF xskxceiver test and changing packet size to 6912 and the requested offset to a huge value, e.g. XSK_UMEM__MAX_FRAME_SIZE * 100. Due to other quirks of the ZC configuration in ice, panic is not observed in ZC mode, but tailroom growing still fails when it should not. Use fill queue buffer truesize instead of DMA write size in XDP RxQ info. Fix ZC mode too by using the new helper. Fixes: 2fba7dc5157b ("ice: Add support for XDP multi-buffer on Rx side") Reviewed-by: Aleksandr Loktionov Signed-off-by: Larysa Zaremba Link: https://patch.msgid.link/20260305111253.2317394-5-larysa.zaremba@intel.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/intel/ice/ice_base.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_base.c b/drivers/net/ethernet/intel/ice/ice_base.c index 165ef8afa8b0..1667f686ff75 100644 --- a/drivers/net/ethernet/intel/ice/ice_base.c +++ b/drivers/net/ethernet/intel/ice/ice_base.c @@ -661,7 +661,6 @@ static int ice_vsi_cfg_rxq(struct ice_rx_ring *ring) { struct device *dev = ice_pf_to_dev(ring->vsi->back); u32 num_bufs = ICE_DESC_UNUSED(ring); - u32 rx_buf_len; int err; if (ring->vsi->type == ICE_VSI_PF || ring->vsi->type == ICE_VSI_SF || @@ -672,12 +671,12 @@ static int ice_vsi_cfg_rxq(struct ice_rx_ring *ring) return err; if (ring->xsk_pool) { - rx_buf_len = - xsk_pool_get_rx_frame_size(ring->xsk_pool); + u32 frag_size = + xsk_pool_get_rx_frag_step(ring->xsk_pool); err = __xdp_rxq_info_reg(&ring->xdp_rxq, ring->netdev, ring->q_index, ring->q_vector->napi.napi_id, - rx_buf_len); + frag_size); if (err) return err; err = xdp_rxq_info_reg_mem_model(&ring->xdp_rxq, @@ -697,7 +696,7 @@ static int ice_vsi_cfg_rxq(struct ice_rx_ring *ring) err = __xdp_rxq_info_reg(&ring->xdp_rxq, ring->netdev, ring->q_index, ring->q_vector->napi.napi_id, - ring->rx_buf_len); + ring->truesize); if (err) goto err_destroy_fq;