[U-Boot] [PATCH v2] usb: xhci: Fix a potential NULL pointer dereference

[Marek Vasut]

On Friday, August 14, 2015 at 05:14:09 PM, Sergey Temerkhanov wrote:
> This patch fixes a potential NULL pointer dereference arising on
> non-present/non-initialized xHCI controllers and adds some error
> handling to xHCI code
> 
> Signed-off-by: Sergey Temerkhanov <s.temerkhanov at gmail.com>
> Signed-off-by: Radha Mohan Chintakuntla <rchintakuntla at cavium.com>
> 
> ---
> 
> Changes in v2:
> - Add return value check with setting hccr and hcor to NULL
> 
>  drivers/usb/host/xhci.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index 0b09643..f8e2d70 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -199,7 +199,7 @@ int xhci_reset(struct xhci_hcor *hcor)
>  	int ret;
> 
>  	/* Halting the Host first */
> -	debug("// Halt the HC\n");
> +	debug("// Halt the HC: %p\n", hcor);
>  	state = xhci_readl(&hcor->or_usbsts) & STS_HALT;
>  	if (!state) {
>  		cmd = xhci_readl(&hcor->or_usbcmd);
> @@ -1079,6 +1079,11 @@ int usb_lowlevel_init(int index, enum usb_init_type
> init, void **controller)
> 
>  	*controller = &xhcic[index];
> 
> +	if (ret) {
> +		ctrl->hccr = NULL;
> +		ctrl->hcor = NULL;

Controller should be set to NULL too, for the sake of being completely precise,
don't you think so ?

> +	}
> +
>  	return ret;
>  }
> 
> @@ -1093,9 +1098,11 @@ int usb_lowlevel_stop(int index)
>  {
>  	struct xhci_ctrl *ctrl = (xhcic + index);
> 
> -	xhci_lowlevel_stop(ctrl);
> -	xhci_hcd_stop(index);
> -	xhci_cleanup(ctrl);
> +	if (ctrl->hcor) {
> +		xhci_lowlevel_stop(ctrl);
> +		xhci_hcd_stop(index);
> +		xhci_cleanup(ctrl);
> +	}
> 
>  	return 0;
>  }

Good job, thanks :)

Best regards,
Marek Vasut