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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, Oz Shlomo <ozsh@nvidia.com>,
        Paul Blakey <paulb@nvidia.com>,
        Saeed Mahameed <saeedm@nvidia.com>
Subject: [PATCH 5.15 050/135] net/mlx5e: CT: Fix queued up restore put() executing after relevant ft release
Date:   Tue, 10 May 2022 15:07:12 +0200
Message-Id: <20220510130741.835869717@linuxfoundation.org>
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From: Paul Blakey <paulb@nvidia.com>

commit b069e14fff46c8da9fcc79957f8acaa3e2dfdb6b upstream.

__mlx5_tc_ct_entry_put() queues release of tuple related to some ct FT,
if that is the last reference to that tuple, the actual deletion of
the tuple can happen after the FT is already destroyed and freed.

Flush the used workqueue before destroying the ct FT.

Fixes: a2173131526d ("net/mlx5e: CT: manage the lifetime of the ct entry object")
Reviewed-by: Oz Shlomo <ozsh@nvidia.com>
Signed-off-by: Paul Blakey <paulb@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
@@ -1699,6 +1699,8 @@ mlx5_tc_ct_flush_ft_entry(void *ptr, voi
 static void
 mlx5_tc_ct_del_ft_cb(struct mlx5_tc_ct_priv *ct_priv, struct mlx5_ct_ft *ft)
 {
+	struct mlx5e_priv *priv;
+
 	if (!refcount_dec_and_test(&ft->refcount))
 		return;
 
@@ -1708,6 +1710,8 @@ mlx5_tc_ct_del_ft_cb(struct mlx5_tc_ct_p
 	rhashtable_free_and_destroy(&ft->ct_entries_ht,
 				    mlx5_tc_ct_flush_ft_entry,
 				    ct_priv);
+	priv = netdev_priv(ct_priv->netdev);
+	flush_workqueue(priv->wq);
 	mlx5_tc_ct_free_pre_ct_tables(ft);
 	mapping_remove(ct_priv->zone_mapping, ft->zone_restore_id);
 	kfree(ft);