net/mlx5e: kTLS, Fix crash in RX resync flow

For the TLS RX resync flow, we maintain a list of TLS contexts
that require some attention, to communicate their resync information
to the HW.
Here we fix list corruptions, by protecting the entries against
movements coming from resync_handle_seq_match(), until their resync
handling in napi is fully completed.

Fixes: e9ce991bce5b ("net/mlx5e: kTLS, Add resiliency to RX resync failures")
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c
index 62abce0..a2a9f68 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_rx.c
@@ -55,6 +55,7 @@ struct mlx5e_ktls_offload_context_rx {
        DECLARE_BITMAP(flags, MLX5E_NUM_PRIV_RX_FLAGS);
 
        /* resync */
+       spinlock_t lock; /* protects resync fields */
        struct mlx5e_ktls_rx_resync_ctx resync;
        struct list_head list;
 };
@@ -386,14 +387,18 @@ static void resync_handle_seq_match(struct mlx5e_ktls_offload_context_rx *priv_r
        struct mlx5e_icosq *sq;
        bool trigger_poll;
 
-       memcpy(info->rec_seq, &priv_rx->resync.sw_rcd_sn_be, sizeof(info->rec_seq));
-
        sq = &c->async_icosq;
        ktls_resync = sq->ktls_resync;
+       trigger_poll = false;
 
        spin_lock_bh(&ktls_resync->lock);
-       list_add_tail(&priv_rx->list, &ktls_resync->list);
-       trigger_poll = !test_and_set_bit(MLX5E_SQ_STATE_PENDING_TLS_RX_RESYNC, &sq->state);
+       spin_lock_bh(&priv_rx->lock);
+       memcpy(info->rec_seq, &priv_rx->resync.sw_rcd_sn_be, sizeof(info->rec_seq));
+       if (list_empty(&priv_rx->list)) {
+               list_add_tail(&priv_rx->list, &ktls_resync->list);
+               trigger_poll = !test_and_set_bit(MLX5E_SQ_STATE_PENDING_TLS_RX_RESYNC, &sq->state);
+       }
+       spin_unlock_bh(&priv_rx->lock);
        spin_unlock_bh(&ktls_resync->lock);
 
        if (!trigger_poll)
@@ -617,6 +622,8 @@ int mlx5e_ktls_add_rx(struct net_device *netdev, struct sock *sk,
        if (err)
                goto err_create_key;
 
+       INIT_LIST_HEAD(&priv_rx->list);
+       spin_lock_init(&priv_rx->lock);
        priv_rx->crypto_info  =
                *(struct tls12_crypto_info_aes_gcm_128 *)crypto_info;
 
@@ -730,10 +737,14 @@ bool mlx5e_ktls_rx_handle_resync_list(struct mlx5e_channel *c, int budget)
                priv_rx = list_first_entry(&local_list,
                                           struct mlx5e_ktls_offload_context_rx,
                                           list);
+               spin_lock(&priv_rx->lock);
                cseg = post_static_params(sq, priv_rx);
-               if (IS_ERR(cseg))
+               if (IS_ERR(cseg)) {
+                       spin_unlock(&priv_rx->lock);
                        break;
-               list_del(&priv_rx->list);
+               }
+               list_del_init(&priv_rx->list);
+               spin_unlock(&priv_rx->lock);
                db_cseg = cseg;
        }
        if (db_cseg)