Re: [PATCH rdma-next] RDMA/cgroup: fix resource leak in DRIVER_FAILURE cleanup path

[Leon Romanovsky <leon@kernel.org>]

On Mon, May 18, 2026 at 11:15:41AM +0800, Tao Cui wrote:
> When a driver fails to destroy an RDMA object during ufile cleanup,
> the kernel retries and eventually falls back to the
> RDMA_REMOVE_DRIVER_FAILURE path. This path sets obj->object = NULL
> before calling uverbs_destroy_uobject(), which skips the destroy_hw
> callback. Since ib_rdmacg_uncharge() lives inside destroy_hw_idr_uobject(),
> the HCA_OBJECT cgroup charge is never released.
> 
> Add an explicit ib_rdmacg_uncharge() call in the DRIVER_FAILURE path
> to prevent the resource counter leak.

It is not the correct approach. A cgroup controls how many resources a  
task may consume, and a "failure to release" indicates that the resource  
usage is still being accounted to that task.

Thanks

> 
> Signed-off-by: Tao Cui <cuitao@kylinos.cn>
> ---
>  drivers/infiniband/core/rdma_core.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c
> index 5018ec837056..347ec8f6976b 100644
> --- a/drivers/infiniband/core/rdma_core.c
> +++ b/drivers/infiniband/core/rdma_core.c
> @@ -917,8 +917,11 @@ static int __uverbs_cleanup_ufile(struct ib_uverbs_file *ufile,
>  		 * racing with a lookup_get.
>  		 */
>  		WARN_ON(uverbs_try_lock_object(obj, UVERBS_LOOKUP_WRITE));
> -		if (reason == RDMA_REMOVE_DRIVER_FAILURE)
> +		if (reason == RDMA_REMOVE_DRIVER_FAILURE) {
>  			obj->object = NULL;
> +			ib_rdmacg_uncharge(&obj->cg_obj, ib_dev,
> +					   RDMACG_RESOURCE_HCA_OBJECT);
> +		}
>  		if (!uverbs_destroy_uobject(obj, reason, &attrs))
>  			ret = 0;
>  		else
> -- 
> 2.43.0
>