Re: [PATCH v3 2/2] cxl: Fix race of nvdimm_bus object when creating nvdimm objects

[Gregory Price <gourry@gourry.net>]

On Fri, Feb 13, 2026 at 03:40:38PM -0700, Dave Jiang wrote:
> @@ -248,6 +262,19 @@ int devm_cxl_add_nvdimm(struct device *host, struct cxl_port *port,
>  	if (!cxl_nvb)
>  		return -ENODEV;
>  
> +	/*
> +	 * Take the uport_dev lock to guard against race of nvdimm_bus object.
> +	 * cxl_acpi_probe() registers the nvdimm_bus and is done under the
> +	 * root port uport_dev lock.
> +	 *
> +	 * Take the cxl_nvb device lock to ensure that cxl_nvb driver is in a
> +	 * consistent state. And the driver registers nvdimm_bus.
> +	 */
> +	guard(device)(cxl_nvb->port->uport_dev);
> +	guard(device)(&cxl_nvb->dev);
> +	if (!cxl_nvb->nvdimm_bus)
> +		return -ENODEV;
> +

I think this leaks the reference on cxl_nvb taken by 

	devm_cxl_add_nvdimm()
		device_find_child()

Maybe:
     if (!cxl_nvb->nvdimm_bus) {
             rc = -ENODEV;
             goto err_alloc;
     }


Reported-by: kreview-0811365

~Gregory