# Re: \[PATCH v7 1/5\] net/mlx5: free mlx5\_st\_idx\_data on final dealloc

- From: Michael Gur \<hidden\>
- Date: 2026-06-14 07:06:46 
- List: netdev
- Page: https://ratatoskr.run/netdev/2026/06/17129797
- Thread: https://ratatoskr.run/netdev/2026/06/17120895/t.md

```text

On 6/11/2026 7:11 PM, Zhiping Zhang wrote:
> When the last reference to an ST table entry is dropped,
> mlx5_st_dealloc_index() removed the entry from idx_xa but leaked the
> backing mlx5_st_idx_data allocation. Repeated alloc/dealloc cycles
> therefore accumulate one struct mlx5_st_idx_data per cycle.
>
> Free idx_data after the xa_erase() so the lifetime of the bookkeeping
> struct matches the lifetime of the ST entry it tracks.
>
> Fixes: 888a7776f4fb ("net/mlx5: Add support for device steering tag")
> Signed-off-by: Zhiping Zhang <redacted>
> ---
>   drivers/net/ethernet/mellanox/mlx5/core/lib/st.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/st.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/st.c
> index 997be91f0a13..7cedc348790d 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/lib/st.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/st.c
> @@ -175,6 +175,7 @@ int mlx5_st_dealloc_index(struct mlx5_core_dev *dev, u16 st_index)
>   
>   	if (refcount_dec_and_test(&idx_data->usecount)) {
>   		xa_erase(&st->idx_xa, st_index);
> +		kfree(idx_data);
>   		/* We leave PCI config space as was before, no mkey will refer to it */
>   	}
>   

Reviewed-by: Michael Gur <redacted>

Thanks.

```