Re: [PATCH v3 2/2] usb: host: max3421: Reject hub port requests for non-existent ports

[Alan Stern <stern@rowland.harvard.edu>]

On Sun, May 17, 2026 at 03:03:08PM -0400, pip-izony wrote:
> From: Seungjin Bae <eeodqql09@gmail.com>
> 
> The `max3421_hub_control()` function handles USB hub class requests
> to the virtual root hub. The `GetPortStatus` case correctly rejects
> requests with `index != 1`, since the virtual root hub has only a
> single port. However, the `ClearPortFeature` and `SetPortFeature`
> cases lack the same check.
> 
> Fix this by extending the `index != 1` rejection to both cases,
> matching the existing behavior of `GetPortStatus`.
> 
> Fixes: 2d53139f3162 ("Add support for using a MAX3421E chip as a host driver.")
> Suggested-by: Alan Stern <stern@rowland.harvard.edu>
> Signed-off-by: Seungjin Bae <eeodqql09@gmail.com>
> ---

Reviewed-by: Alan Stern <stern@rowland.harvard.edu>

Heh, this made me go back and look at dummy-hcd.c.  It's missing the 
same check in the same places!

Would you like to submit a patch to fix that driver as well?  If not, 
I'll take care of it.

Alan Stern

>  v3: New patch in v3, suggested by Alan Stern.
> 
>  drivers/usb/host/max3421-hcd.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/usb/host/max3421-hcd.c b/drivers/usb/host/max3421-hcd.c
> index 3d6b351dcb1a..73e76d0e6973 100644
> --- a/drivers/usb/host/max3421-hcd.c
> +++ b/drivers/usb/host/max3421-hcd.c
> @@ -1685,6 +1685,8 @@ max3421_hub_control(struct usb_hcd *hcd, u16 type_req, u16 value, u16 index,
>  	case ClearHubFeature:
>  		break;
>  	case ClearPortFeature:
> +		if (index != 1)
> +			goto error;
>  		switch (value) {
>  		case USB_PORT_FEAT_SUSPEND:
>  			break;
> @@ -1728,6 +1730,8 @@ max3421_hub_control(struct usb_hcd *hcd, u16 type_req, u16 value, u16 index,
>  		break;
>  
>  	case SetPortFeature:
> +		if (index != 1)
> +			goto error;
>  		switch (value) {
>  		case USB_PORT_FEAT_LINK_STATE:
>  		case USB_PORT_FEAT_U1_TIMEOUT:
> -- 
> 2.43.0
>