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* [PATCH v2] staging: emxx_udc: Add checks for dma_alloc_coherent()
@ 2023-01-19  2:34 Yuan Can
  2023-01-19  5:17 ` Dan Carpenter
  0 siblings, 1 reply; 4+ messages in thread
From: Yuan Can @ 2023-01-19  2:34 UTC (permalink / raw)
  To: gregkh, drv, damm+renesas, horms+renesas, linux-staging; +Cc: yuancan

As the dma_alloc_coherent may return NULL, the return value needs to be
checked to avoid NULL poineter dereference.

Fixes: 33aa8d45a4fe ("staging: emxx_udc: Add Emma Mobile USB Gadget driver")
Signed-off-by: Yuan Can <yuancan@huawei.com>
---
changes in v2:
- do the null pointer check right before the memcpy().

 drivers/staging/emxx_udc/emxx_udc.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/emxx_udc/emxx_udc.c b/drivers/staging/emxx_udc/emxx_udc.c
index b4e19174bef2..4fce1a9a659c 100644
--- a/drivers/staging/emxx_udc/emxx_udc.c
+++ b/drivers/staging/emxx_udc/emxx_udc.c
@@ -2592,9 +2592,15 @@ static int nbu2ss_ep_queue(struct usb_ep *_ep,
 							  &ep->phys_buf,
 							  GFP_ATOMIC | GFP_DMA);
 		if (ep->epnum > 0)  {
-			if (ep->direct == USB_DIR_IN)
-				memcpy(ep->virt_buf, req->req.buf,
-				       req->req.length);
+			if (ep->direct == USB_DIR_IN) {
+				if (!ep->virt_buf) {
+					spin_unlock_irqrestore(&udc->lock,
+							       flags);
+					return -ENOMEM;
+				} else
+					memcpy(ep->virt_buf, req->req.buf,
+					       req->req.length);
+			}
 		}
 	}
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] staging: emxx_udc: Add checks for dma_alloc_coherent()
  2023-01-19  2:34 [PATCH v2] staging: emxx_udc: Add checks for dma_alloc_coherent() Yuan Can
@ 2023-01-19  5:17 ` Dan Carpenter
  2023-01-19  8:25   ` Yuan Can
  2023-01-19 10:47   ` Simon Horman
  0 siblings, 2 replies; 4+ messages in thread
From: Dan Carpenter @ 2023-01-19  5:17 UTC (permalink / raw)
  To: Yuan Can; +Cc: gregkh, drv, damm+renesas, horms+renesas, linux-staging

On Thu, Jan 19, 2023 at 02:34:30AM +0000, Yuan Can wrote:
> As the dma_alloc_coherent may return NULL, the return value needs to be
> checked to avoid NULL poineter dereference.
> 
> Fixes: 33aa8d45a4fe ("staging: emxx_udc: Add Emma Mobile USB Gadget driver")
> Signed-off-by: Yuan Can <yuancan@huawei.com>
> ---
> changes in v2:
> - do the null pointer check right before the memcpy().
> 

No. No.  This should be:

diff --git a/drivers/staging/emxx_udc/emxx_udc.c b/drivers/staging/emxx_udc/emxx_udc.c
index b4e19174bef2..f9765841c4aa 100644
--- a/drivers/staging/emxx_udc/emxx_udc.c
+++ b/drivers/staging/emxx_udc/emxx_udc.c
@@ -2587,10 +2587,15 @@ static int nbu2ss_ep_queue(struct usb_ep *_ep,
 		req->unaligned = false;
 
 	if (req->unaligned) {
-		if (!ep->virt_buf)
+		if (!ep->virt_buf) {
 			ep->virt_buf = dma_alloc_coherent(udc->dev, PAGE_SIZE,
 							  &ep->phys_buf,
 							  GFP_ATOMIC | GFP_DMA);
+			if (!ep->virt_buf) {
+				spin_unlock_irqrestore(&udc->lock, flags);
+				return -ENOMEM;
+			}
+		}
 		if (ep->epnum > 0)  {
 			if (ep->direct == USB_DIR_IN)
 				memcpy(ep->virt_buf, req->req.buf,

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] staging: emxx_udc: Add checks for dma_alloc_coherent()
  2023-01-19  5:17 ` Dan Carpenter
@ 2023-01-19  8:25   ` Yuan Can
  2023-01-19 10:47   ` Simon Horman
  1 sibling, 0 replies; 4+ messages in thread
From: Yuan Can @ 2023-01-19  8:25 UTC (permalink / raw)
  To: Dan Carpenter; +Cc: gregkh, drv, damm+renesas, horms+renesas, linux-staging


在 2023/1/19 13:17, Dan Carpenter 写道:
> On Thu, Jan 19, 2023 at 02:34:30AM +0000, Yuan Can wrote:
>> As the dma_alloc_coherent may return NULL, the return value needs to be
>> checked to avoid NULL poineter dereference.
>>
>> Fixes: 33aa8d45a4fe ("staging: emxx_udc: Add Emma Mobile USB Gadget driver")
>> Signed-off-by: Yuan Can <yuancan@huawei.com>
>> ---
>> changes in v2:
>> - do the null pointer check right before the memcpy().
>>
> No. No.  This should be:
>
> diff --git a/drivers/staging/emxx_udc/emxx_udc.c b/drivers/staging/emxx_udc/emxx_udc.c
> index b4e19174bef2..f9765841c4aa 100644
> --- a/drivers/staging/emxx_udc/emxx_udc.c
> +++ b/drivers/staging/emxx_udc/emxx_udc.c
> @@ -2587,10 +2587,15 @@ static int nbu2ss_ep_queue(struct usb_ep *_ep,
>   		req->unaligned = false;
>   
>   	if (req->unaligned) {
> -		if (!ep->virt_buf)
> +		if (!ep->virt_buf) {
>   			ep->virt_buf = dma_alloc_coherent(udc->dev, PAGE_SIZE,
>   							  &ep->phys_buf,
>   							  GFP_ATOMIC | GFP_DMA);
> +			if (!ep->virt_buf) {
> +				spin_unlock_irqrestore(&udc->lock, flags);
> +				return -ENOMEM;
> +			}
> +		}
>   		if (ep->epnum > 0)  {
>   			if (ep->direct == USB_DIR_IN)
>   				memcpy(ep->virt_buf, req->req.buf,
Ok, thanks for this!

-- 
Best regards,
Yuan Can


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH v2] staging: emxx_udc: Add checks for dma_alloc_coherent()
  2023-01-19  5:17 ` Dan Carpenter
  2023-01-19  8:25   ` Yuan Can
@ 2023-01-19 10:47   ` Simon Horman
  1 sibling, 0 replies; 4+ messages in thread
From: Simon Horman @ 2023-01-19 10:47 UTC (permalink / raw)
  To: Dan Carpenter; +Cc: Yuan Can, gregkh, drv, damm+renesas, linux-staging

On Thu, Jan 19, 2023 at 08:17:12AM +0300, Dan Carpenter wrote:
> On Thu, Jan 19, 2023 at 02:34:30AM +0000, Yuan Can wrote:
> > As the dma_alloc_coherent may return NULL, the return value needs to be
> > checked to avoid NULL poineter dereference.
> > 
> > Fixes: 33aa8d45a4fe ("staging: emxx_udc: Add Emma Mobile USB Gadget driver")
> > Signed-off-by: Yuan Can <yuancan@huawei.com>
> > ---
> > changes in v2:
> > - do the null pointer check right before the memcpy().
> > 
> 
> No. No.  This should be:
> 
> diff --git a/drivers/staging/emxx_udc/emxx_udc.c b/drivers/staging/emxx_udc/emxx_udc.c
> index b4e19174bef2..f9765841c4aa 100644
> --- a/drivers/staging/emxx_udc/emxx_udc.c
> +++ b/drivers/staging/emxx_udc/emxx_udc.c
> @@ -2587,10 +2587,15 @@ static int nbu2ss_ep_queue(struct usb_ep *_ep,
>  		req->unaligned = false;
>  
>  	if (req->unaligned) {
> -		if (!ep->virt_buf)
> +		if (!ep->virt_buf) {
>  			ep->virt_buf = dma_alloc_coherent(udc->dev, PAGE_SIZE,
>  							  &ep->phys_buf,
>  							  GFP_ATOMIC | GFP_DMA);
> +			if (!ep->virt_buf) {
> +				spin_unlock_irqrestore(&udc->lock, flags);
> +				return -ENOMEM;
> +			}
> +		}
>  		if (ep->epnum > 0)  {
>  			if (ep->direct == USB_DIR_IN)
>  				memcpy(ep->virt_buf, req->req.buf,
> 

Yes, FWIIW, I think so too.

Reviewed-by: Simon Horman <horms@verge.net.au>


^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2023-01-19 10:55 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-01-19  2:34 [PATCH v2] staging: emxx_udc: Add checks for dma_alloc_coherent() Yuan Can
2023-01-19  5:17 ` Dan Carpenter
2023-01-19  8:25   ` Yuan Can
2023-01-19 10:47   ` Simon Horman

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