Re: [PATCH] net/mlx5: fix crash on deleting flow drop queue

["Nélio Laranjeiro" <nelio.laranjeiro@6wind.com>]

On Mon, May 01, 2017 at 02:05:42PM -0700, Yongseok Koh wrote:
> If mlx5_dev_start() fails, it tries to rollback data structures related to
> rte_flow including drop queue. The destruction code doesn't assume the
> structures are created but priv_flow_delete_drop_queue() never does sanity
> check. This can cause a crash.
> 
> Fixes: 028761059aeb ("net/mlx5: use an RSS drop queue")
> 
> Signed-off-by: Yongseok Koh <yskoh@mellanox.com>
> ---
>  drivers/net/mlx5/mlx5_flow.c | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
> index cd3e5daf3..adcbe3f52 100644
> --- a/drivers/net/mlx5/mlx5_flow.c
> +++ b/drivers/net/mlx5/mlx5_flow.c
> @@ -1465,13 +1465,18 @@ priv_flow_delete_drop_queue(struct priv *priv)
>  	struct rte_flow_drop *fdq = priv->flow_drop_queue;
>  	unsigned int i;
>  
> -	claim_zero(ibv_destroy_qp(fdq->qp));
> -	claim_zero(ibv_exp_destroy_rwq_ind_table(fdq->ind_table));
> +	if (!fdq)
> +		return;
> +	if (fdq->qp)
> +		claim_zero(ibv_destroy_qp(fdq->qp));
> +	if (fdq->ind_table)
> +		claim_zero(ibv_exp_destroy_rwq_ind_table(fdq->ind_table));
>  	for (i = 0; i != MLX5_DROP_WQ_N; ++i) {
> -		assert(fdq->wqs[i]);
> -		claim_zero(ibv_exp_destroy_wq(fdq->wqs[i]));
> +		if (fdq->wqs[i])
> +			claim_zero(ibv_exp_destroy_wq(fdq->wqs[i]));
>  	}
> -	claim_zero(ibv_destroy_cq(fdq->cq));
> +	if (fdq->cq)
> +		claim_zero(ibv_destroy_cq(fdq->cq));
>  	rte_free(fdq);
>  	priv->flow_drop_queue = NULL;
>  }
> -- 
> 2.11.0
 

Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>

-- 
Nélio Laranjeiro
6WIND