From: Xiaomeng Tong <xiam0nd.tong@xxxxxxxxx> commit 3f95a7472d14abef284d8968734fe2ae7ff4845f upstream. The bug is here: ret = i40e_add_macvlan_filter(hw, ch->seid, vdev->dev_addr, &aq_err); The list iterator 'ch' will point to a bogus position containing HEAD if the list is empty or no element is found. This case must be checked before any use of the iterator, otherwise it will lead to a invalid memory access. To fix this bug, use a new variable 'iter' as the list iterator, while use the origin variable 'ch' as a dedicated pointer to point to the found element. Cc: stable@xxxxxxxxxxxxxxx Fixes: 1d8d80b4e4ff6 ("i40e: Add macvlan support on i40e") Signed-off-by: Xiaomeng Tong <xiam0nd.tong@xxxxxxxxx> Tested-by: Gurucharan <gurucharanx.g@xxxxxxxxx> (A Contingent worker at Intel) Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx> Link: https://lore.kernel.org/r/20220510204846.2166999-1-anthony.l.nguyen@xxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/intel/i40e/i40e_main.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -7175,42 +7175,43 @@ static void i40e_free_macvlan_channels(s static int i40e_fwd_ring_up(struct i40e_vsi *vsi, struct net_device *vdev, struct i40e_fwd_adapter *fwd) { + struct i40e_channel *ch = NULL, *ch_tmp, *iter; int ret = 0, num_tc = 1, i, aq_err; - struct i40e_channel *ch, *ch_tmp; struct i40e_pf *pf = vsi->back; struct i40e_hw *hw = &pf->hw; - if (list_empty(&vsi->macvlan_list)) - return -EINVAL; - /* Go through the list and find an available channel */ - list_for_each_entry_safe(ch, ch_tmp, &vsi->macvlan_list, list) { - if (!i40e_is_channel_macvlan(ch)) { - ch->fwd = fwd; + list_for_each_entry_safe(iter, ch_tmp, &vsi->macvlan_list, list) { + if (!i40e_is_channel_macvlan(iter)) { + iter->fwd = fwd; /* record configuration for macvlan interface in vdev */ for (i = 0; i < num_tc; i++) netdev_bind_sb_channel_queue(vsi->netdev, vdev, i, - ch->num_queue_pairs, - ch->base_queue); - for (i = 0; i < ch->num_queue_pairs; i++) { + iter->num_queue_pairs, + iter->base_queue); + for (i = 0; i < iter->num_queue_pairs; i++) { struct i40e_ring *tx_ring, *rx_ring; u16 pf_q; - pf_q = ch->base_queue + i; + pf_q = iter->base_queue + i; /* Get to TX ring ptr */ tx_ring = vsi->tx_rings[pf_q]; - tx_ring->ch = ch; + tx_ring->ch = iter; /* Get the RX ring ptr */ rx_ring = vsi->rx_rings[pf_q]; - rx_ring->ch = ch; + rx_ring->ch = iter; } + ch = iter; break; } } + if (!ch) + return -EINVAL; + /* Guarantee all rings are updated before we update the * MAC address filter. */