2022-03-29 09:25:10

by CGEL

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

From: Lv Ruyi <[email protected]>

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 <[email protected]>
Signed-off-by: Lv Ruyi <[email protected]>
---
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;
+ }
udc->status_req->req.dma = DMA_ADDR_INVALID;

udc->resume_state = USB_STATE_NOTATTACHED;
--
2.25.1

2022-03-30 12:15:29

by Christophe JAILLET

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

Le 29/03/2022 à 07:54, [email protected] a écrit :
> From: Lv Ruyi <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Lv Ruyi <[email protected]>
> ---
> 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;

2022-03-31 03:46:25

by Shuah Khan

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

On 3/28/22 11:54 PM, [email protected] wrote:
> From: Lv Ruyi <[email protected]>
>
> kzalloc() is a memory allocation function which can return NULL when some
> internal memory errors happen. It is safer to check NULL pointer.
>

Please add information on how this problem was found, including the
tool used and warn message.

> Reported-by: Zeal Robot <[email protected]>
> Signed-off-by: Lv Ruyi <[email protected]>
> ---
> 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;
> + }

Looks good to me.

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

With that change to the commit log

Reviewed-by: Shuah Khan <[email protected]>

thanks,
-- Shuah