Re: [PATCH 2/2] RDMA/nldev: Guard against NULL ucontext in resource dumps

[Jason Gunthorpe]

On Tue, Aug 11, 2026 at 06:56:23PM +0800, Yili Zhang wrote:
> +	/*
> +	 * The uobject's context is cleared by uverbs_destroy_uobject() during
> +	 * the RDMA_REMOVE_DRIVER_FAILURE fallback path, while the CQ itself is
> +	 * leaked in the restrack xarray (its destroy failed, so neither the HW
> +	 * CQ nor the restrack entry can be torn down). A concurrent dump must
> +	 * not oops when it stumbles onto such a half-destroyed user CQ.
> +	 */
> +	if (!rdma_is_kernel_res(res)) {
> +		struct ib_ucontext *ctx =
> +			READ_ONCE(cq->uobject->uevent.uobject.context);
> +
> +		if (ctx && nla_put_u32(msg, RDMA_NLDEV_ATTR_RES_CTXN,
> +				       ctx->res.id))
> +			return -EMSGSIZE;
> +	}

It is missing locking right? This needs to run under the disassociate
srcu probably

Jason