Re: [PATCH 2/2] usbip: vhci_hcd: reduce CONFIG_USBIP_VHCI_NR_HCS upper bound to 32

[Shuah Khan <skhan@linuxfoundation.org>]

On 4/13/26 19:00, Adrian Wowk wrote:
> Each VHCI HC instance registers two USB buses (one HS, one SS).
> USB_MAXBUS in drivers/usb/core/hcd.c is hard-coded to 64, giving an
> effective maximum of 32 VHCI HC instances (32 * 2 = 64 buses).
> 
> The Kconfig range for USBIP_VHCI_NR_HCS currently allows up to 128,
> which will cause probe failures for any HC instance beyond the 32nd.
> These probe failures trigger the NULL pointer dereference fixed in the
> previous commit.
> 
> Reduce the upper bound to 32 to reflect the real maximum imposed by
> USB_MAXBUS. Note that probe failures can still occur below this limit
> if real hardware has already claimed enough USB bus numbers, making
> the NULL check fix necessary regardless.
> 
> Signed-off-by: Adrian Wowk <dev@adrianwowk.com>
> ---
>   drivers/usb/usbip/Kconfig | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/usbip/Kconfig b/drivers/usb/usbip/Kconfig
> index b9f94e2e278..50945b6fae1 100644
> --- a/drivers/usb/usbip/Kconfig
> +++ b/drivers/usb/usbip/Kconfig
> @@ -40,7 +40,7 @@ config USBIP_VHCI_HC_PORTS
>   
>   config USBIP_VHCI_NR_HCS
>   	int "Number of USB/IP virtual host controllers"
> -	range 1 128
> +	range 1 32
>   	default 1
>   	depends on USBIP_VHCI_HCD
>   	help

Looks good to me.

Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>

Greg, Please pick this up.

thanks,
-- Shuah