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Date:   Thu, 2 Jun 2022 08:45:28 +0200
From:   Johan Hovold <johan@kernel.org>
To:     Dongliang Mu <dzm91@hust.edu.cn>
Cc:     Mauro Carvalho Chehab <mchehab@kernel.org>,
        gushengxian <gushengxian@yulong.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Oliver Neukum <oneukum@suse.com>, Sean Young <sean@mess.org>,
        Dongliang Mu <mudongliangabcd@gmail.com>,
        Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] media: flexcop-usb: fix sanity check of bNumEndpoints
Message-ID: <YphciEToNtxIUrzU@hovoldconsulting.com>
References: <20220602055027.849014-1-dzm91@hust.edu.cn>
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On Thu, Jun 02, 2022 at 01:50:24PM +0800, Dongliang Mu wrote:
> From: Dongliang Mu <mudongliangabcd@gmail.com>
> 
> Commit d725d20e81c2 ("media: flexcop-usb: sanity checking of endpoint type
> ") adds a sanity check for endpoint[1], but fails to modify the sanity
> check of bNumEndpoints.
> 
> Fix this by modifying the sanity check of bNumEndpoints to 2.

Are you sure that d725d20e81c2 ("media: flexcop-usb: sanity checking of
endpoint type) was correct?

> Fixes: d725d20e81c2 ("media: flexcop-usb: sanity checking of endpoint type")
> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> ---
>  drivers/media/usb/b2c2/flexcop-usb.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/media/usb/b2c2/flexcop-usb.c b/drivers/media/usb/b2c2/flexcop-usb.c
> index 7835bb0f32fc..eb54bfdda01f 100644
> --- a/drivers/media/usb/b2c2/flexcop-usb.c
> +++ b/drivers/media/usb/b2c2/flexcop-usb.c
> @@ -509,7 +509,7 @@ static int flexcop_usb_init(struct flexcop_usb *fc_usb)
>  		return ret;
>  	}
>  
> -	if (fc_usb->uintf->cur_altsetting->desc.bNumEndpoints < 1)
> +	if (fc_usb->uintf->cur_altsetting->desc.bNumEndpoints < 2)
>  		return -ENODEV;
>  	if (!usb_endpoint_is_isoc_in(&fc_usb->uintf->cur_altsetting->endpoint[1].desc))
>  		return -ENODEV;

It looks like it should have verified the type of endpoint[0] here
instead.

Oliver?

Johan