[PATCH 5.12 118/296] net/mlx5e: reset XPS on error flow if netdev isnt registered yet

Greg Kroah-Hartman
2021-05-31T16:18:21Z

From: Saeed Mahameed <saeedm@nvidia.com>

commit 77ecd10d0a8aaa6e4871d8c63626e4c9fc5e47db upstream.

mlx5e_attach_netdev can be called prior to registering the netdevice:
Example stack:

ipoib_new_child_link ->
ipoib_intf_init->
rdma_init_netdev->
mlx5_rdma_setup_rn->

mlx5e_attach_netdev->
mlx5e_num_channels_changed ->
mlx5e_set_default_xps_cpumasks ->
netif_set_xps_queue ->
__netif_set_xps_queue -> kmalloc

If any later stage fails at any point after mlx5e_num_channels_changed()
returns, XPS allocated maps will never be freed as they
are only freed during netdev unregistration, which will never happen for
yet to be registered netdevs.

Fixes: 3909a12e7913 ("net/mlx5e: Fix configuration of XPS cpumasks and netdev queues in corner cases")
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 7 +++++++
1 file changed, 7 insertions(+)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -5604,6 +5604,11 @@ static void mlx5e_update_features(struct
rtnl_unlock();
}

+static void mlx5e_reset_channels(struct net_device *netdev)
+{
+ netdev_reset_tc(netdev);
+}
+
int mlx5e_attach_netdev(struct mlx5e_priv *priv)
{
const bool take_rtnl = priv->netdev->reg_state == NETREG_REGISTERED;
@@ -5658,6 +5663,7 @@ err_cleanup_tx:
profile->cleanup_tx(priv);

out:
+ mlx5e_reset_channels(priv->netdev);
set_bit(MLX5E_STATE_DESTROYING, &priv->state);
cancel_work_sync(&priv->update_stats_work);
return err;
@@ -5675,6 +5681,7 @@ void mlx5e_detach_netdev(struct mlx5e_pr

profile->cleanup_rx(priv);
profile->cleanup_tx(priv);
+ mlx5e_reset_channels(priv->netdev);
cancel_work_sync(&priv->update_stats_work);
}