Re: [PATCH 6/7] cxl/pci: Check memdev driver binding status in cxl_reset_done()

[Dave Jiang]

On 3/10/26 8:57 AM, Li Ming wrote:
> cxl_reset_done() accesses the endpoint of the corresponding CXL memdev
> without endpoint validity checking. By default, cxlmd->endpoint is
> initialized to -ENXIO, if cxl_reset_done() is triggered after the
> corresponding CXL memdev probing failed, this results in access to an
> invalid endpoint.
> 
> CXL subsystem can always check CXL memdev driver binding status to
> confirm its endpoint validity. So adding the CXL memdev driver checking
> inside cxl_reset_done() to avoid accessing an invalid endpoint.
> 
> Fixes: 934edcd436dc ("cxl: Add post-reset warning if reset results in loss of previously committed HDM decoders")
> Signed-off-by: Li Ming <ming.li@xxxxxxxxxxxx>

Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>

> ---
>  drivers/cxl/pci.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
> index fbb300a01830..a5922116db2a 100644
> --- a/drivers/cxl/pci.c
> +++ b/drivers/cxl/pci.c
> @@ -1043,6 +1043,9 @@ static void cxl_reset_done(struct pci_dev *pdev)
>  	 * that no longer exists.
>  	 */
>  	guard(device)(&cxlmd->dev);
> +	if (!cxlmd->dev.driver)
> +		return;
> +
>  	if (cxlmd->endpoint &&
>  	    cxl_endpoint_decoder_reset_detected(cxlmd->endpoint)) {
>  		dev_crit(dev, "SBR happened without memory regions removal.\n");
>