net/mlx4: fix drop queue mem alloc failure handle

  The function mlx4_drop_get() creates pointer to a struct mlx4_drop and
if needed allocates by rte_malloc.

If the allocation is failed the function goes to label “error”, and
there does dereference to a null pointer.

Skip resources cleaning when the memory allocation is failed.

Coverity issue: 146206
Coverity issue: 146146
Fixes: d3a7e09234e4 ("net/mlx4: allocate drop flow resources on demand")
Cc: stable@dpdk.org

Signed-off-by: Michael Baum <michaelba@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>
---
 drivers/net/mlx4/mlx4_flow.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)
  

Hi,
> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Michael Baum
> Sent: Wednesday, May 6, 2020 7:28 PM
> To: dev@dpdk.org
> Cc: Matan Azrad <matan@mellanox.com>; Slava Ovsiienko
> <viacheslavo@mellanox.com>; stable@dpdk.org
> Subject: [dpdk-dev] [PATCH] net/mlx4: fix drop queue mem alloc failure
> handle
> 
> The function mlx4_drop_get() creates pointer to a struct mlx4_drop and
> if needed allocates by rte_malloc.
> 
> If the allocation is failed the function goes to label “error”, and
> there does dereference to a null pointer.
> 
> Skip resources cleaning when the memory allocation is failed.
> 
> Coverity issue: 146206
> Coverity issue: 146146
> Fixes: d3a7e09234e4 ("net/mlx4: allocate drop flow resources on demand")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Michael Baum <michaelba@mellanox.com>
> Acked-by: Matan Azrad <matan@mellanox.com>
> ---
>  drivers/net/mlx4/mlx4_flow.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/mlx4/mlx4_flow.c b/drivers/net/mlx4/mlx4_flow.c
> index 793f0b0..2a86382 100644
> --- a/drivers/net/mlx4/mlx4_flow.c
> +++ b/drivers/net/mlx4/mlx4_flow.c
> @@ -980,12 +980,13 @@ struct mlx4_drop {
>  	priv->drop = drop;
>  	return drop;
>  error:
> -	if (drop->qp)
> -		claim_zero(mlx4_glue->destroy_qp(drop->qp));
> -	if (drop->cq)
> -		claim_zero(mlx4_glue->destroy_cq(drop->cq));
> -	if (drop)
> +	if (drop) {
> +		if (drop->qp)
> +			claim_zero(mlx4_glue->destroy_qp(drop->qp));
> +		if (drop->cq)
> +			claim_zero(mlx4_glue->destroy_cq(drop->cq));
>  		rte_free(drop);
> +	}
>  	rte_errno = ENOMEM;
>  	return NULL;
>  }
> --
> 1.8.3.1

Patch applied to next-net-mlx,

Kindest regards,
Raslan Darawsheh