Re: [PATCH net v2] net/mlx5: free mlx5_st_idx_data on final dealloc
From: Paolo Abeni
Date: Fri Jul 10 2026 - 07:29:18 EST
On 7/3/26 12:24 AM, Zhiping Zhang wrote:
> Workloads that repeatedly allocate and release mkeys carrying TPH
> steering-tag hints (e.g. churning RDMA MRs) leak one
> struct mlx5_st_idx_data per cycle; kmemleak flags it as unreferenced
> and the kmalloc slab grows over time.
>
> When the last reference to an ST table entry is dropped,
> mlx5_st_dealloc_index() removed the entry from idx_xa but the backing
> mlx5_st_idx_data allocation was never freed.
>
> Free idx_data after the xa_erase() so the lifetime of the bookkeeping
> struct matches the lifetime of the ST entry it tracks.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: 888a7776f4fb ("net/mlx5: Add support for device steering tag")
> Reviewed-by: Michael Gur <michaelgur@xxxxxxxxxx>
> Signed-off-by: Zhiping Zhang <zhipingz@xxxxxxxx>
@Leon, @Saeed, @Tariq: just in case this fell under the radar, it's
waiting for your ack.
Thanks,
Paolo