Re: [PATCH] usb: gadget: udc: add NULL pointer check

From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
To: cgel.zte@gmail.com, balbi@kernel.org
Cc: gregkh@linuxfoundation.org, peter.chen@kernel.org,
	skhan@linuxfoundation.org, lv.ruyi@zte.com.cn, johan@kernel.org,
	jakobkoschel@gmail.com, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org, Zeal Robot <zealci@zte.com.cn>
Subject: Re: [PATCH] usb: gadget: udc: add NULL pointer check
Date: Tue, 29 Mar 2022 20:47:38 +0200	[thread overview]
Message-ID: <63e05f0a-6fb0-c7dc-0c3a-467a5c4e11da@wanadoo.fr> (raw)
In-Reply-To: <20220329055407.2375626-1-lv.ruyi@zte.com.cn>

Le 29/03/2022 à 07:54, cgel.zte@gmail.com a écrit :
> From: Lv Ruyi <lv.ruyi@zte.com.cn>
>
> kzalloc() is a memory allocation function which can return NULL when some
> internal memory errors happen. It is safer to check NULL pointer.
>
> Reported-by: Zeal Robot <zealci@zte.com.cn>
> Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn>
> ---
>   drivers/usb/gadget/udc/mv_udc_core.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/usb/gadget/udc/mv_udc_core.c b/drivers/usb/gadget/udc/mv_udc_core.c
> index fdb17d86cd65..f52eb3f2420a 100644
> --- a/drivers/usb/gadget/udc/mv_udc_core.c
> +++ b/drivers/usb/gadget/udc/mv_udc_core.c
> @@ -2231,6 +2231,10 @@ static int mv_udc_probe(struct platform_device *pdev)
>   
>   	/* allocate a small amount of memory to get valid address */
>   	udc->status_req->req.buf = kzalloc(8, GFP_KERNEL);
> +	if (!udc->status_req->req.buf) {
> +		retval = -ENOMEM;
> +		goto err_destroy_dma;
> +	}

Hi,

not directly related to this patch, but I wonder if this kzalloc should 
be freed in the error handling path, and maybe also in the .remove 
function. It seems to be leaking.

CJ

>   	udc->status_req->req.dma = DMA_ADDR_INVALID;
>   
>   	udc->resume_state = USB_STATE_NOTATTACHED;