Re: [PATCH -next] usb: gadget: hid: fix error return code

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Jun 17, 2021 at 02:56:25PM +0800, Yang Yingliang wrote:
> Fix to return a negative error code from the error handling
> case instead of 0.
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> ---
>  drivers/usb/gadget/legacy/hid.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/gadget/legacy/hid.c b/drivers/usb/gadget/legacy/hid.c
> index c4eda7fe7ab4..3912cc805f3a 100644
> --- a/drivers/usb/gadget/legacy/hid.c
> +++ b/drivers/usb/gadget/legacy/hid.c
> @@ -99,8 +99,10 @@ static int do_config(struct usb_configuration *c)
>  
>  	list_for_each_entry(e, &hidg_func_list, node) {
>  		e->f = usb_get_function(e->fi);
> -		if (IS_ERR(e->f))
> +		if (IS_ERR(e->f)) {
> +			status = PTR_ERR(e->f);

Are you _SURE_ that you now want to return an error?  This code has
never done this, what is going to break now that it will?

>  			goto put;
> +		}
>  		status = usb_add_function(c, e->f);
>  		if (status < 0) {
>  			usb_put_function(e->f);
> @@ -171,8 +173,10 @@ static int hid_bind(struct usb_composite_dev *cdev)
>  		struct usb_descriptor_header *usb_desc;
>  
>  		usb_desc = usb_otg_descriptor_alloc(gadget);
> -		if (!usb_desc)
> +		if (!usb_desc) {
> +			status = -ENOMEM;

This looks correct, can you resend just this chunk, and then go test the
above change to verify it doesn't break things?

thanks,

greg k-h