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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Saeed Mahameed <saeedm@nvidia.com>,
        Aya Levin <ayal@nvidia.com>, Tariq Toukan <tariqt@nvidia.com>
Subject: [PATCH 5.10 097/252] net/mlx5e: reset XPS on error flow if netdev isnt registered yet
Date:   Mon, 31 May 2021 15:12:42 +0200
Message-Id: <20210531130701.279525401@linuxfoundation.org>
In-Reply-To: <20210531130657.971257589@linuxfoundation.org>
References: <20210531130657.971257589@linuxfoundation.org>
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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
@@ -5385,6 +5385,11 @@ err_free_netdev:
 	return NULL;
 }
 
+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;
@@ -5438,6 +5443,7 @@ 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;
@@ -5455,6 +5461,7 @@ 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);
 }